Bump cachix/install-nix-action from 25 to 26 (#2738)

Bumps [cachix/install-nix-action](https://github.com/cachix/install-nix-action) from 25 to 26.
- [Release notes](https://github.com/cachix/install-nix-action/releases)
- [Commits](cachix/install-nix-action@v25...v26)

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

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

.github/workflows/build_nix.yml

@@ -23,7 +23,7 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Install Nix
-        uses: cachix/install-nix-action@v25
+        uses: cachix/install-nix-action@v26
 
       - name: Nix Caching
         uses: cachix/cachix-action@v14

.github/workflows/careful.yml

@@ -16,7 +16,7 @@ jobs:
     timeout-minutes: 120
     steps:
       - name: Install Nix
-        uses: cachix/install-nix-action@v25
+        uses: cachix/install-nix-action@v26
 
       - name: Nix Caching
         uses: cachix/cachix-action@v14

.github/workflows/coverage.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Install Nix
-        uses: cachix/install-nix-action@v25
+        uses: cachix/install-nix-action@v26
 
       - name: Nix Caching
         uses: cachix/cachix-action@v14

.github/workflows/update_nix.yml

@@ -16,7 +16,7 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Install Nix
-        uses: cachix/install-nix-action@v25
+        uses: cachix/install-nix-action@v26
         with:
           extra_nix_config: |
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}