Bump cachix/install-nix-action from V28 to 30 (#1105)

Author: dependabot[bot]

.github/workflows/nix-action-coq-8.16-macos.yml

@@ -19,7 +19,7 @@ jobs:
         fetch-depth: 0
         ref: ${{ env.tested_commit }}
     - name: Cachix install
-      uses: cachix/install-nix-action@V28
+      uses: cachix/install-nix-action@v30
       with:
         nix_path: nixpkgs=channel:nixpkgs-unstable
     - name: Cachix setup metacoq
@@ -59,7 +59,7 @@ jobs:
         fetch-depth: 0
         ref: ${{ env.tested_commit }}
     - name: Cachix install
-      uses: cachix/install-nix-action@V28
+      uses: cachix/install-nix-action@v30
       with:
         nix_path: nixpkgs=channel:nixpkgs-unstable
     - name: Cachix setup metacoq
@@ -104,7 +104,7 @@ jobs:
         fetch-depth: 0
         ref: ${{ env.tested_commit }}
     - name: Cachix install
-      uses: cachix/install-nix-action@V28
+      uses: cachix/install-nix-action@v30
       with:
         nix_path: nixpkgs=channel:nixpkgs-unstable
     - name: Cachix setup metacoq

.github/workflows/nix-action-coq-8.16-ubuntu.yml

@@ -19,7 +19,7 @@ jobs:
         fetch-depth: 0
         ref: ${{ env.tested_commit }}
     - name: Cachix install
-      uses: cachix/install-nix-action@V28
+      uses: cachix/install-nix-action@v30
       with:
         nix_path: nixpkgs=channel:nixpkgs-unstable
     - name: Cachix setup metacoq
@@ -59,7 +59,7 @@ jobs:
         fetch-depth: 0
         ref: ${{ env.tested_commit }}
     - name: Cachix install
-      uses: cachix/install-nix-action@V28
+      uses: cachix/install-nix-action@v30
       with:
         nix_path: nixpkgs=channel:nixpkgs-unstable
     - name: Cachix setup metacoq
@@ -104,7 +104,7 @@ jobs:
         fetch-depth: 0
         ref: ${{ env.tested_commit }}
     - name: Cachix install
-      uses: cachix/install-nix-action@V28
+      uses: cachix/install-nix-action@v30
       with:
         nix_path: nixpkgs=channel:nixpkgs-unstable
     - name: Cachix setup metacoq