Modify test-build workflow for multiple Python versions

Updated the workflow to support Python versions 3.14 and 3.15, changed language from 'XX' to 'de', and added installation step for rsvg-convert.

Author: sba72

.github/workflows/test-build.yml

@@ -1,5 +1,5 @@
 name: Test Build Workflow
-
+# changed to 3.14, 3.15
 on:
   schedule:
     - cron: '0 0 * * *'
@@ -14,7 +14,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        version: [ '3.14' ]
+        version: [ '3.15', '3.14' ]
         format: [ html, latex ]
     steps:
       - uses: actions/setup-python@master
@@ -26,14 +26,16 @@ jobs:
           ref: ${{ matrix.version }}
       - run: make venv
         working-directory: ./Doc
+      - name: Install rsvg-convert
+        run: sudo apt-get update && sudo apt-get install -y librsvg2-bin
       - uses: actions/checkout@master
         with:
           ref: ${{ matrix.version }}
-          path: Doc/locales/XX/LC_MESSAGES
+          path: Doc/locales/de/LC_MESSAGES
       - run: git pull
-        working-directory: ./Doc/locales/XX/LC_MESSAGES
+        working-directory: ./Doc/locales/de/LC_MESSAGES
       - uses: sphinx-doc/github-problem-matcher@v1.1
-      - run: make -e SPHINXOPTS="--color -D language='XX' -W --keep-going" ${{ matrix.format }}
+      - run: make -e SPHINXOPTS="--color -D language='de' -D suppress_warnings=i18n.inconsistent_references -W --keep-going" ${{ matrix.format }}
         working-directory: ./Doc
       - uses: actions/upload-artifact@master
         if: success() || failure()
@@ -45,7 +47,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        version: [ '3.14' ]
+        version: [ '3.15', '3.14' ]
     needs: [ 'build-translation' ]
     steps:
       - uses: actions/download-artifact@master