fix(ci): use PAT for release-please and simplify test matrix

Use RELEASE_PAT instead of GITHUB_TOKEN in release-please workflow
so that created releases can trigger the publish workflow. Simplify
test matrix to Python 3.12 only.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: alperensert

.github/workflows/release-please.yml

@@ -15,6 +15,6 @@ jobs:
     steps:
       - uses: googleapis/release-please-action@v4
         with:
-          token: ${{ secrets.GITHUB_TOKEN }}
+          token: ${{ secrets.RELEASE_PAT }}
           config-file: .release-please-config.json
           manifest-file: .release-please-manifest.json

.github/workflows/tests.yml

@@ -14,21 +14,17 @@ on:
 jobs:
   test:
     runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        python-version: ['3.9', '3.10', '3.11', '3.12']
-
     env:
       API_KEY: ${{ secrets.API_KEY }}
 
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
 
-      - name: Set up Python ${{ matrix.python-version }}
+      - name: Set up Python
         uses: actions/setup-python@v5
         with:
-          python-version: ${{ matrix.python-version }}
+          python-version: '3.12'
 
       - name: Install dependencies
         run: |