chore: pin actions (#134)

Author: stephantul

.github/workflows/ci.yaml

@@ -19,7 +19,7 @@ jobs:
         python-version: ["3.10", "3.11", "3.12", "3.13", "3.14"]
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5
 
       - name: Set up Python ${{ matrix.python-version }} on ${{ matrix.os }}
         uses: actions/setup-python@v5
@@ -28,7 +28,7 @@ jobs:
           allow-prereleases: true
 
       - name: Install uv
-        uses: astral-sh/setup-uv@v6
+        uses: astral-sh/setup-uv@d0d8abe699bfb85fec6de9f7adb5ae17292296ff
 
       - name: Create virtual environment
         run: uv venv .venv
@@ -53,6 +53,6 @@ jobs:
         run: pytest
 
       - name: Upload results to Codecov
-        uses: codecov/codecov-action@v4
+        uses: codecov/codecov-action@b9fd7d16f6d7d1b5d2bec1a2887e65ceed900238
         with:
           token: ${{ secrets.CODECOV_TOKEN }}