test: ignore IAB capabilities in test-execute

libcap v2.33 introduces a new capability set called IAB[0] which is shown
in the output of `capsh --print` and interferes with the test checks. Let's
drop the IAB set from the output, for now, to mitigate this.

This could be (and probably should be) replaced in the future by the
newly introduced testing options[1][2] in libcap v2.32, namely:
    --has-p=xxx
    --has-i=xxx
    --has-a=xxx

but this needs to wait until the respective libcap version gets a wider
adoption. Until then, let's stick with the relatively ugly sed.

Fixes: #15046

[0] https://git.kernel.org/pub/scm/libs/libcap/libcap.git/commit/?id=943b011b5e53624eb9cab4e96c1985326e077cdd
[1] https://git.kernel.org/pub/scm/libs/libcap/libcap.git/commit/?id=588d0439cb6495b03f0ab9f213f0b6b339e7d4b7
[2] https://git.kernel.org/pub/scm/libs/libcap/libcap.git/commit/?id=e7709bbc1c4712f2ddfc6e6f42892928a8a03782

test/test-execute/exec-capabilityboundingset-invert.service

@@ -2,7 +2,7 @@
 Description=Test for CapabilityBoundingSet
 
 [Service]
-# sed: remove dropped capabilities (cap_xxx-[epi]) from the output
+# sed: remove dropped (cap_xxx-[epi]) and IAB capabilities from the output
-ExecStart=/bin/sh -x -c '! capsh --print | sed -r "s/[^ ]+?\-[epi]+//g" | grep "^Bounding set .*cap_chown"'
+ExecStart=/bin/sh -x -c '! capsh --print | sed -re "s/[^ ]+?\-[epi]+//g" -e '/IAB/d' | grep "^Bounding set .*cap_chown"'
 Type=oneshot
 CapabilityBoundingSet=~CAP_CHOWN

test/test-execute/exec-privatedevices-no-capability-mknod.service

@@ -3,6 +3,6 @@ Description=Test CAP_MKNOD capability for PrivateDevices=no
 
 [Service]
 PrivateDevices=no
-# sed: remove dropped capabilities (cap_xxx-[epi]) from the output
+# sed: remove dropped (cap_xxx-[epi]) and IAB capabilities from the output
-ExecStart=/bin/sh -x -c 'capsh --print | sed -r "s/[^ ]+?\-[epi]+//g" | grep cap_mknod'
+ExecStart=/bin/sh -x -c 'capsh --print | sed -re "s/[^ ]+?\-[epi]+//g" -e '/IAB/d' | grep cap_mknod'
 Type=oneshot

test/test-execute/exec-privatedevices-no-capability-sys-rawio.service

@@ -3,6 +3,6 @@ Description=Test CAP_SYS_RAWIO capability for PrivateDevices=no
 
 [Service]
 PrivateDevices=no
-# sed: remove dropped capabilities (cap_xxx-[epi]) from the output
+# sed: remove dropped (cap_xxx-[epi]) and IAB capabilities from the output
-ExecStart=/bin/sh -x -c 'capsh --print | sed -r "s/[^ ]+?\-[epi]+//g" | grep cap_sys_rawio'
+ExecStart=/bin/sh -x -c 'capsh --print | sed -re "s/[^ ]+?\-[epi]+//g" -e '/IAB/d' | grep cap_sys_rawio'
 Type=oneshot

test/test-execute/exec-privatedevices-yes-capability-mknod.service

@@ -3,6 +3,6 @@ Description=Test CAP_MKNOD capability for PrivateDevices=yes
 
 [Service]
 PrivateDevices=yes
-# sed: remove dropped capabilities (cap_xxx-[epi]) from the output
+# sed: remove dropped (cap_xxx-[epi]) and IAB capabilities from the output
-ExecStart=/bin/sh -x -c '! capsh --print | sed -r "s/[^ ]+?\-[epi]+//g" | grep cap_mknod'
+ExecStart=/bin/sh -x -c '! capsh --print | sed -re "s/[^ ]+?\-[epi]+//g" -e '/IAB/d' | grep cap_mknod'
 Type=oneshot

test/test-execute/exec-privatedevices-yes-capability-sys-rawio.service

@@ -3,6 +3,6 @@ Description=Test CAP_SYS_RAWIO capability for PrivateDevices=yes
 
 [Service]
 PrivateDevices=yes
-# sed: remove dropped capabilities (cap_xxx-[epi]) from the output
+# sed: remove dropped (cap_xxx-[epi]) and IAB capabilities from the output
-ExecStart=/bin/sh -x -c '! capsh --print | sed -r "s/[^ ]+?\-[epi]+//g" | grep cap_sys_rawio'
+ExecStart=/bin/sh -x -c '! capsh --print | sed -re "s/[^ ]+?\-[epi]+//g" -e '/IAB/d' | grep cap_sys_rawio'
 Type=oneshot

test/test-execute/exec-protectkernellogs-no-capabilities.service

@@ -3,6 +3,6 @@ Description=Test CAP_SYSLOG for ProtectKernelLogs=no
 
 [Service]
 ProtectKernelLogs=no
-# sed: remove dropped capabilities (cap_xxx-[epi]) from the output
+# sed: remove dropped (cap_xxx-[epi]) and IAB capabilities from the output
-ExecStart=/bin/sh -x -c 'capsh --print | sed -r "s/[^ ]+?\-[epi]+//g" | grep cap_syslog'
+ExecStart=/bin/sh -x -c 'capsh --print | sed -re "s/[^ ]+?\-[epi]+//g" -e '/IAB/d' | grep cap_syslog'
 Type=oneshot

test/test-execute/exec-protectkernellogs-yes-capabilities.service

@@ -3,6 +3,6 @@ Description=Test CAP_SYSLOG for ProtectKernelLogs=yes
 
 [Service]
 ProtectKernelLogs=yes
-# sed: remove dropped capabilities (cap_xxx-[epi]) from the output
+# sed: remove dropped (cap_xxx-[epi]) and IAB capabilities from the output
-ExecStart=/bin/sh -x -c '! capsh --print | sed -r "s/[^ ]+?\-[epi]+//g" | grep cap_syslog'
+ExecStart=/bin/sh -x -c '! capsh --print | sed -re "s/[^ ]+?\-[epi]+//g" -e '/IAB/d' | grep cap_syslog'
 Type=oneshot

test/test-execute/exec-protectkernelmodules-no-capabilities.service

@@ -3,6 +3,6 @@ Description=Test CAP_SYS_MODULE ProtectKernelModules=no
 
 [Service]
 ProtectKernelModules=no
-# sed: remove dropped capabilities (cap_xxx-[epi]) from the output
+# sed: remove dropped (cap_xxx-[epi]) and IAB capabilities from the output
-ExecStart=/bin/sh -x -c 'capsh --print | sed -r "s/[^ ]+?\-[epi]+//g" | grep cap_sys_module'
+ExecStart=/bin/sh -x -c 'capsh --print | sed -re "s/[^ ]+?\-[epi]+//g" -e '/IAB/d' | grep cap_sys_module'
 Type=oneshot

test/test-execute/exec-protectkernelmodules-yes-capabilities.service

@@ -3,6 +3,6 @@ Description=Test CAP_SYS_MODULE for ProtectKernelModules=yes
 
 [Service]
 ProtectKernelModules=yes
-# sed: remove dropped capabilities (cap_xxx-[epi]) from the output
+# sed: remove dropped (cap_xxx-[epi]) and IAB capabilities from the output
-ExecStart=/bin/sh -x -c '! capsh --print | sed -r "s/[^ ]+?\-[epi]+//g" | grep cap_sys_module'
+ExecStart=/bin/sh -x -c '! capsh --print | sed -re "s/[^ ]+?\-[epi]+//g" -e '/IAB/d' | grep cap_sys_module'
 Type=oneshot