chore(ci): update GitHub Actions runner to self-hosted (#556)

* chore(ci): update GitHub Actions runner to self-hosted for improved disk space

* chore(ci): update Python version specification in GitHub Actions workflow to '3.12.x'

Author: eliteprox

.github/workflows/test.yaml

@@ -56,7 +56,8 @@ jobs:
 
   test:
     name: Run Tests
-    runs-on: ubuntu-latest
+    runs-on: [self-hosted, linux, amd64]
+    # self-hosted runner provides enough disk space for the full test suite
     steps:
       - name: Check out code
         uses: actions/checkout@v6
@@ -68,7 +69,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v6
         with:
-          python-version: '3.12'
+          python-version: '3.12.x'
           cache: pip
 
       - name: Install dependencies