CI(deps): Update DeterminateSystems/determinate-nix-action action to v3.11.1 (OSGeo#6323)

Author: renovate[bot]

.github/workflows/test-nix.yml

@@ -33,7 +33,7 @@ jobs:
           persist-credentials: false
 
       - name: Install nix
-        uses: DeterminateSystems/determinate-nix-action@fd3eb131b9b46cc1dd978a7c0ba3fce79dd7d3eb # v3.9.1
+        uses: DeterminateSystems/determinate-nix-action@a7e500c712ad97316904566d98013596e868d2fb # v3.11.1
 
       - name: Setup cachix
         uses: cachix/cachix-action@0fc020193b5a1fa3ac4575aa3a7d3aa6a35435ad # v16