Update cachix/install-nix-action action to v31.10.6

Author: renovate[bot]

.github/workflows/nix-integration-test.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
-      - uses: cachix/install-nix-action@ab739621df7a23f52766f9ccc97f38da6b7af14f # v31.10.5
+      - uses: cachix/install-nix-action@8aa03977d8d733052d78f4e008a241fd1dbf36b3 # v31.10.6
         with:
           extra_nix_config: |
             extra-trusted-public-keys = hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ=