docker/ci: Pin action (#3374)

Signed-off-by: Ryan Northey <ryan@synca.io>

Author: phlax

.github/workflows/docker.yml

@@ -72,7 +72,7 @@ jobs:
       shell: bash
 
     - name: Upload OCI artifacts
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@b7c566a772e6b6bfb58ed0dc250532a479d7789f  # v6.0.0
       with:
         name: oci-debian-${{ matrix.arch }}
         path: docker/build/oci-output/*.tar