test-cases: Remove obsolete tests

These tests were not referenced by any template and therefore don't have
a group.

Because no templates were referencing them, they were not executed as
part of the automated test suite. Their removal doesn't affect the test
results.

test-cases/apparmor-pulseaudio.yaml

-metadata:
-  name: apparmor-pulseaudio
-  format: "Apertis Test Definition 1.0"
-  image-types:
-    hmi:     [ armhf, amd64 ]
-    basesdk: [ amd64 ]
-    sdk:     [ amd64 ]
-  image-deployment:
-    - APT
-    - OSTree
-  type: functional
-  exec-type: automated
-  priority: medium
-  maintainer: "Apertis Project"
-  description: "Test that AppArmor profiles provided in PulseAudio work without
-                apparmor complaining."
-
-  expected:
-    - "Both tests should report pass and not fail:"
-    - |
-        >pulseaudio.normal.expected: pass
-        pulseaudio.malicious.expected: pass
-
-  notes:
-    - "The results of the tests printed to the standard output are enough to
-       determine whether they passed or fail."
-    - "If you get a failure and need to report a bug please check journalctl, run
-       the test case again, and add the logs you get to the bug report."
-
-install:
-  git-repos:
-    - url: https://gitlab.apertis.org/tests/apparmor-pulseaudio.git
-      branch: 'apertis/v2023dev1'
-
-run:
-  steps:
-    - "# Enter test directory:"
-    - cd apparmor-pulseaudio
-    - "# Execute the following command:"
-    - common/run-test-in-systemd --name=apparmor-pulseaudio --timeout 90 ./run-test.sh
-

test-cases/apparmor-tumbler.yaml

-metadata:
-  name: apparmor-tumbler
-  format: "Apertis Test Definition 1.0"
-  image-types:
-    hmi:     [ armhf, amd64 ]
-    basesdk: [ amd64 ]
-    sdk:     [ amd64 ]
-  image-deployment:
-    - APT
-    - OSTree
-  type: functional
-  exec-type: automated
-  priority: medium
-  maintainer: "Apertis Project"
-
-  description: "Tests that the tumbler AppArmor profile doesn't cause false negatives and
-                that it does not allow arbitrary reading of files in the home
-                directory."
-
-  expected:
-    - "Both tests should report pass and not fail:"
-    - |
-        >tumbler.normal.expected: pass
-        tumbler.malicious.expected: pass
-
-  notes:
-    - "The results of the tests printed to the standard output are enough to
-       determine whether they passed or fail."
-    - "If you get a failure and need to report a bug please check journalctl, run
-       the test case again, and add the logs you get to the bug report."
-install:
-  git-repos:
-    - url: https://gitlab.apertis.org/tests/apparmor-tumbler.git
-      branch: 'apertis/v2023dev1'
-
-run:
-  steps:
-    - "# Enter test directory:"
-    - cd apparmor-tumbler
-    - "# Execute the following commands:"
-    - common/run-test-in-systemd --name=apparmor-tumbler --timeout 900 ./run-test.sh
-