Bump cachix/install-nix-action from 29 to 30 (#40)

Bumps [cachix/install-nix-action](https://github.com/cachix/install-nix-action) from 29 to 30.
- [Release notes](https://github.com/cachix/install-nix-action/releases)
- [Commits](https://github.com/cachix/install-nix-action/compare/v29...v30)

---
updated-dependencies:
- dependency-name: cachix/install-nix-action
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/dotnet.yaml

@@ -44,7 +44,7 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
       - name: Install Nix
-        uses: cachix/install-nix-action@v29
+        uses: cachix/install-nix-action@v30
         with:
           extra_nix_config: |
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
@@ -59,7 +59,7 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
       - name: Install Nix
-        uses: cachix/install-nix-action@v29
+        uses: cachix/install-nix-action@v30
         with:
           extra_nix_config: |
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
@@ -72,7 +72,7 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
       - name: Install Nix
-        uses: cachix/install-nix-action@v29
+        uses: cachix/install-nix-action@v30
         with:
           extra_nix_config: |
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
@@ -85,7 +85,7 @@ jobs:
     steps:
       - uses: actions/checkout@master
       - name: Install Nix
-        uses: cachix/install-nix-action@v29
+        uses: cachix/install-nix-action@v30
         with:
           extra_nix_config: |
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}