chore(deps): bump actions/setup-python from 5 to 6

Bumps [actions/setup-python](https://github.com/actions/setup-python) from 5 to 6.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](https://github.com/actions/setup-python/compare/v5...v6)

---
updated-dependencies:
- dependency-name: actions/setup-python
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/ci.yml

@@ -256,7 +256,7 @@ jobs:
           path: target/debug
 
       - name: Install python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: ${{ matrix.python }}
 
@@ -303,7 +303,7 @@ jobs:
           persist-credentials: false
 
       - name: Install python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: ${{ matrix.python }}
 

.github/workflows/deltachat-rpc-server.yml

@@ -224,7 +224,7 @@ jobs:
 
       # Python 3.11 is needed for tomllib used in scripts/wheel-rpc-server.py
       - name: Install python 3.12
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: 3.12
 
@@ -289,7 +289,7 @@ jobs:
         with:
           show-progress: false
           persist-credentials: false
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@v6
         with:
           python-version: "3.11"