ci(manual-test): convert from a matrix job to a single job

With this change, the `manual-test` workflow accepts user input as to
what runner OS or Docker image to run on.

It is more useful this way, too, as I never encountered a situation
where I would want to run this Action on multiple runners, having to log
in concurrently into multiple tmate sessions, and I doubt that anyone
else has encountered that situation, either.

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

.github/workflows/manual-test.yml

@@ -1,12 +1,13 @@
 name: Manual test matrix
-on: workflow_dispatch
-
-jobs:
-  test:
-    strategy:
-      fail-fast: false
-      matrix:
-        runs-on:
+on:
+  workflow_dispatch:
+    inputs:
+      runs-on:
+        type: choice
+        description: 'The runner pool to run the job on'
+        required: true
+        default: 'ubuntu-22.04'
+        options:
           - ubuntu-22.04
           - ubuntu-24.04
           - macos-13
@@ -15,31 +16,42 @@ jobs:
           - windows-2019
           - windows-2022
           - windows-2025
-        limit-access-to-actor:
-          - true
-          - false
-    runs-on: ${{ matrix.runs-on }}
+      container-runs-on:
+        type: choice
+        description: 'The Docker container to run the job on (this overrides the `runs-on` input)'
+        required: false
+        default: '(none)'
+        options:
+          - '(none)'
+          - fedora:latest
+          - archlinux:latest
+          - ubuntu:latest
+      limit-access-to-actor:
+        type: choice
+        description: 'Whether to limit access to the actor only'
+        required: true
+        default: 'auto'
+        options:
+          - auto
+          - 'true'
+          - 'false'
+
+jobs:
+  test:
+    if: ${{ inputs.container-runs-on == '(none)' }}
+    runs-on: ${{ inputs.runs-on }}
     steps:
       - uses: actions/checkout@v4
       - uses: ./
         with:
-          limit-access-to-actor: ${{ matrix.limit-access-to-actor }}
+          limit-access-to-actor: ${{ inputs.limit-access-to-actor }}
   test-container:
-    strategy:
-      fail-fast: false
-      matrix:
-        container-runs-on:
-          - fedora:latest
-          - archlinux:latest
-          - ubuntu:latest
-        limit-access-to-actor:
-          - true
-          - false
+    if: ${{ inputs.container-runs-on != '(none)' }}
     runs-on: ubuntu-latest
     container:
-      image: ${{ matrix.container-runs-on }}
+      image: ${{ inputs.container-runs-on }}
     steps:
       - uses: actions/checkout@v4
       - uses: ./
         with:
-          limit-access-to-actor: ${{ matrix.limit-access-to-actor }}
+          limit-access-to-actor: ${{ inputs.limit-access-to-actor }}