Bump GitHub Actions and fix PyPy issue link (#176)

Author: hugovk

.github/workflows/build.yml

@@ -45,7 +45,7 @@ jobs:
           - "pypy3.11"
 
           # Old PyPy versions
-          # See https://foss.heptapod.net/pypy/pypy/-/issues/3991
+          # See https://github.com/pypy/pypy/issues/3990
           - "pypy3.6-v7.3.2"
           - "pypy3.7-v7.3.2"
 
@@ -109,10 +109,10 @@ jobs:
 
     steps:
         # https://github.com/actions/checkout
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v7
       - name: Setup Python
         # https://github.com/actions/setup-python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@v7
         with:
           python-version: ${{ matrix.python }}
           allow-prereleases: true