chore: pin update dependencies actions

Author: rr3khan

.github/workflows/update-flake-dependencies.yml

@@ -9,8 +9,8 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v6
-      - uses: DeterminateSystems/nix-installer-action@v22
-      - uses: DeterminateSystems/magic-nix-cache-action@v13
+      - uses: DeterminateSystems/nix-installer-action@ef8a148080ab6020fd15196c2084a2eea5ff2d25 # v22
+      - uses: DeterminateSystems/magic-nix-cache-action@565684385bcd71bad329742eefe8d12f2e765b39 # v13
         with:
           use-flakehub: false
       - name: Update flake.lock and create signed commit with flake.lock changes