Update GitHub actions to most recent versions (#136)

Author: seifertm

.github/workflows/pants.yaml

@@ -23,11 +23,11 @@ jobs:
       matrix:
         python-version: [3.9]
     steps:
-    - uses: actions/checkout@v3
-    - uses: actions/setup-python@v4
+    - uses: actions/checkout@v4
+    - uses: actions/setup-python@v5
       with:
         python-version: ${{ matrix.python-version }}
-    - uses: pantsbuild/actions/init-pants@v5-scie-pants
+    - uses: pantsbuild/actions/init-pants@v8
       # This action bootstraps pants and manages 2-3 GHA caches.
       # See: github.com/pantsbuild/actions/tree/main/init-pants/
       with: