Update action versions and Python versions in GitHub Actions testing workflow.

Author: lapets

.github/workflows/build-publish-sign-release.yml

@@ -14,9 +14,9 @@ jobs:
       - call-workflow-lint-test-cover-docs
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Install Python.
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v6
         with:
           python-version: 3.12
           architecture: x64
@@ -42,7 +42,7 @@ jobs:
       id-token: write
     steps:
       - name: Download all the package distributions.
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v5
         with:
           name: python-package-distributions
           path: dist/
@@ -58,12 +58,12 @@ jobs:
       id-token: write # For Sigstore.
     steps:
       - name: Download all the package distributions.
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v5
         with:
           name: python-package-distributions
           path: dist/
       - name: Sign the package distributions with Sigstore.
-        uses: sigstore/gh-action-sigstore-python@v3.0.0
+        uses: sigstore/gh-action-sigstore-python@v3.0.1
         with:
           inputs: >-
             ./dist/*.tar.gz

.github/workflows/lint-test-cover-docs.yml

@@ -6,13 +6,13 @@ on:
   workflow_call: # If invoked by build-publish-sign-release workflow.
 jobs:
   lint_test_cover_docs:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ['3.7', '3.8', '3.9', '3.10', '3.11', '3.12']
+        python-version: ['3.9', '3.10', '3.11', '3.12', '3.13']
     name: Python ${{ matrix.python-version }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Install Python.
         uses: actions/setup-python@v5
         with: