Revert "test: skip TEST-13-NSPAWN.nspawn/machined, TEST-86-MULTI-PROFILE-UKI and TEST-07-PID1.private-pids.sh"

The release is done, re-enable the skipped flaky tests for main.

This reverts commit ab828def6d.

test/TEST-86-MULTI-PROFILE-UKI/meson.build

@@ -6,6 +6,5 @@ integration_tests += [
                 'storage' : 'persistent',
                 'vm' : true,
                 'firmware' : 'auto',
-                'enabled' : false,
         },
 ]

test/units/TEST-07-PID1.sh

@@ -10,7 +10,6 @@ set -o pipefail
 # See TEST-07-PID1/test.sh for the first "half" of the test
 mountpoint /issue2730
 
-export TEST_SKIP_SUBTESTS="private-pids"
 run_subtests
 
 touch /testok

test/units/TEST-13-NSPAWN.sh

@@ -13,7 +13,6 @@ fi
 # shellcheck source=test/units/test-control.sh
 . "$(dirname "$0")"/test-control.sh
 
-export TEST_SKIP_SUBTESTS="nspawn machined"
 run_subtests
 
 touch /testok