Harden github CI for conda building using refs for actions (#43)

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Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: ggeorgakoudis

.github/workflows/build-containers.yml

@@ -8,20 +8,20 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Set up QEMU
-        uses: docker/setup-qemu-action@v3
+        uses: docker/setup-qemu-action@c7c53464625b32c7a7e944ae62b3e17d2b600130
 
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3
+        uses: docker/setup-buildx-action@8d2750c68a42422c14e847fe6c8ac0403b4cbd6f
 
       - name: Login to GitHub Container Registry
-        uses: docker/login-action@v3
+        uses: docker/login-action@c94ce9fb468520275223c153574b00df6fe4bcc9
         with:
           registry: ghcr.io
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Build and push pyomp container
-        uses: docker/build-push-action@v6
+        uses: docker/build-push-action@263435318d21b8e681c14492fe198d362a7d2c83
         with:
           platforms: linux/amd64,linux/arm64
           file: buildscripts/containers/Dockerfile

.github/workflows/build-upload-conda.yml

@@ -36,14 +36,14 @@ jobs:
             echo "CONDA_LABEL=main" >> $GITHUB_ENV
           fi
 
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5
         # Checkout the repo with history to get the commit hash for the build
         # string.
         with:
           fetch-depth: 0
 
       - name: Create and activate conda env
-        uses: conda-incubator/setup-miniconda@v3
+        uses: conda-incubator/setup-miniconda@fc2d68f6413eb2d87b895e92f8584b5b94a10167
         with:
           python-version: "3.12"
           auto-update-conda: false