Automatically fix the nix hash

This pull requests lets the action directly push to the pr to fix the
nix hash.

.github/workflows/checks.yml

@@ -30,4 +30,11 @@ jobs:
         run: |
             echo "If the job is failing with: \"hash mismatch in fixed-output derivation\""
             echo "Copy the hash after \"got:\" and replace \"npmDepsHash\" in \"flake-module.nix\" with the hash"
-            ! nix develop --command "exit 1" 2>&1 | grep "hash mismatch" -A2
+            nix develop --command "exit 1" 2>shell_output
+            ! cat shell_output | grep "hash mismatch" -A2
+            # Filter the hash and then replace it in `flake-module.nix`
+            cat shell_output | grep "got:" | sed "s/[ \t]*got:[ \t]*//" > hash
+            sed "s@npmDepsHash = \"[^\"]*\"@npmDepsHash = \"$(cat hash)\"@" -i flake-module.nix
+       - uses: stefanzweifel/git-auto-commit-action@v5
+         with:
+           commit_message: "Fix nix hash"