Bump cachix/install-nix-action from V28 to 30

Bumps [cachix/install-nix-action](https://github.com/cachix/install-nix-action) from V28 to 30. This release includes the previously tagged commit.
- [Release notes](https://github.com/cachix/install-nix-action/releases)
- [Commits](cachix/install-nix-action@V28...v30)

---
updated-dependencies:
- dependency-name: cachix/install-nix-action
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/cache-updated.yml

@@ -24,7 +24,7 @@ jobs:
       - uses: fregante/setup-git-user@v2
         if: steps.changed-files.outputs.any_changed == 'true'
       - name: Install Nix
-        uses: cachix/install-nix-action@V28
+        uses: cachix/install-nix-action@v30
         if: steps.changed-files.outputs.any_changed == 'true'
         with:
           extra_nix_config: 'experimental-features = nix-command flakes'

.github/workflows/rebuild-cache.yml

@@ -10,7 +10,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: fregante/setup-git-user@v2
       - name: Install Nix
-        uses: cachix/install-nix-action@V28
+        uses: cachix/install-nix-action@v30
         with:
           extra_nix_config: 'experimental-features = nix-command flakes'
           nix_path: nixpkgs=channel:nixos-unstable

.github/workflows/update-charts.yml

@@ -12,7 +12,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: fregante/setup-git-user@v2
       - name: Install Nix
-        uses: cachix/install-nix-action@V28
+        uses: cachix/install-nix-action@v30
         with:
           extra_nix_config: 'experimental-features = nix-command flakes'
           nix_path: nixpkgs=channel:nixos-unstable