.github: move setup-mkdocs to kernelkit/actions

Finishes the migration started in 63f46d4d: setup-mkdocs was still
referenced via a relative ./.github/actions path, which GitHub resolves
against the calling repo, not infix, breaking spins (e.g. Styx) that
reuse build.yml/build-release.yml. Use kernelkit/actions/setup-mkdocs@v1.2.

Signed-off-by: Richard Alpe <richard@bit42.se>

.github/actions/setup-mkdocs/action.yml

@@ -1,20 +0,0 @@
-name: 'Setup MkDocs'
-description: "Install MkDocs and the plugins required to build the Infix User's Guide (post-build.sh bundles it into WebUI images)."
-
-# Mirrors the dependency set in .github/workflows/docs.yml.  Kept in-repo
-# (rather than an external action) so any checkout of a commit needing
-# docs-in-image can reproduce it without an out-of-tree dependency.
-runs:
-  using: composite
-  steps:
-    - name: Install MkDocs and plugins
-      shell: bash
-      run: |
-        command -v pipx >/dev/null 2>&1 || python3 -m pip install --user pipx
-        python3 -m pipx install --force mkdocs
-        python3 -m pipx inject mkdocs \
-          mkdocs-material pymdown-extensions mkdocs-callouts mike mkdocs-to-pdf mkdocs-glightbox
-        # Make the pipx-installed mkdocs visible to later steps (the build,
-        # where post-build.sh invokes it).
-        python3 -m pipx environment --value PIPX_BIN_DIR >> "$GITHUB_PATH" 2>/dev/null \
-          || echo "$HOME/.local/bin" >> "$GITHUB_PATH"

.github/workflows/build-release.yml

@@ -46,7 +46,7 @@ jobs:
           enabled: ${{ inputs.use_cache }}
 
       # WebUI images bundle the mkdocs User's Guide via post-build.sh.
-      - uses: ./.github/actions/setup-mkdocs
+      - uses: kernelkit/actions/setup-mkdocs@v1.2
 
       - name: Configure & Build
         env:

.github/workflows/build.yml

@@ -125,7 +125,7 @@ jobs:
           target: ${{ env.TARGET }}
 
       # WebUI images bundle the mkdocs User's Guide via post-build.sh.
-      - uses: ./.github/actions/setup-mkdocs
+      - uses: kernelkit/actions/setup-mkdocs@v1.2
 
       - name: Configure ${{ env.TARGET }}
         run: |