ci: Remove nix actions cache and prepopulate job

The nix actions cache currently leads to repeated "no space left on
devices" errors for jobs in CI.

The prepopulate job is useless without the nix actions cache, so it
will go away at the same time.

.github/actions/setup-nix/action.yaml

@@ -7,9 +7,6 @@ inputs:
     description: Token to pass to cachix
   tools:
     description: Tools to install with nix-env -iA <tools>
-  cache-id:
-    description: Cache id to use for cache-nix-action
-    default: "default"
 
 runs:
   using: composite
@@ -17,13 +14,7 @@ runs:
     - uses: nixbuild/nix-quick-install-action@v26
       with:
         nix_version: '2.13.6'
-    - name: Restore and cache Nix store
+    - uses: cachix/cachix-action@v14
-      uses: nix-community/cache-nix-action@v4.0.3
-      with:
-        key: cache-nix-${{ runner.os }}-id-${{ inputs.cache-id }}-${{ hashFiles('nix/**/*.nix', '.github/actions/setup-nix/*') }}
-        restore-keys: |
-          cache-nix-${{ runner.os }}-common-
-    - uses: cachix/cachix-action@v13
       with:
         name: postgrest
         authToken: ${{ inputs.authToken }}

.github/workflows/ci.yaml

@@ -18,32 +18,15 @@ concurrency:
   cancel-in-progress: "${{ github.event_name == 'pull_request' }}"
 
 jobs:
-  Prepopulate-Nix-Cache-Linux:
-    name: Prepopulate Nix cache for Linux runners
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - name: Setup Nix Environment
-        uses: ./.github/actions/setup-nix
-        with:
-          cache-id: common
-      - name: Put all tools to store to be cached afterwards
-        run: |
-          # shellcheck disable=SC2046
-          nix-store -v --realize $( nix-instantiate default.nix )
-        shell: bash
-    
   Lint-Style:
     name: Lint & check code style
     runs-on: ubuntu-latest
-    needs: [Prepopulate-Nix-Cache-Linux]
     steps:
       - uses: actions/checkout@v4
       - name: Setup Nix Environment
         uses: ./.github/actions/setup-nix
         with:
           tools: style
-          cache-id: common
       - name: Run linter (check locally with `nix-shell --run postgrest-lint`)
         run: postgrest-lint
       - name: Run style check (auto-format with `nix-shell --run postgrest-style`)
@@ -53,7 +36,6 @@ jobs:
   Test-Nix:
     name: Test (Nix)
     runs-on: ubuntu-latest
-    needs: [Prepopulate-Nix-Cache-Linux]
     defaults:
       run:
         # Hack for enabling color output, see:
@@ -65,7 +47,6 @@ jobs:
         uses: ./.github/actions/setup-nix
         with:
           tools: tests
-          cache-id: common
 
       - name: Run coverage (IO tests and Spec tests against PostgreSQL 15)
         run: postgrest-coverage
@@ -91,7 +72,6 @@ jobs:
         pgVersion: [9.6, 10, 11, 12, 13, 14, 15, 16]
     name: Test PG ${{ matrix.pgVersion }} (Nix)
     runs-on: ubuntu-latest
-    needs: [Prepopulate-Nix-Cache-Linux]
     defaults:
       run:
         # Hack for enabling color output, see:
@@ -103,9 +83,6 @@ jobs:
         uses: ./.github/actions/setup-nix
         with:
           tools: tests withTools
-          # It seems like they are installing the same set of derivations, so we can assign them the same cache id. 
-          # This would decrease the amount of caches dowloaded on merge cache step and will prevent disk space issues.
-          cache-id: common 
 
       - name: Run spec tests
         if: always()
@@ -119,14 +96,12 @@ jobs:
   Test-Memory-Nix:
     name: Test memory (Nix)
     runs-on: ubuntu-latest
-    needs: [Prepopulate-Nix-Cache-Linux]
     steps:
       - uses: actions/checkout@v4
       - name: Setup Nix Environment
         uses: ./.github/actions/setup-nix
         with:
           tools: memory
-          cache-id: common
       - name: Run memory tests
         run: postgrest-test-memory
 
@@ -134,14 +109,12 @@ jobs:
   Build-Static-Nix:
     name: Build Linux static (Nix)
     runs-on: ubuntu-latest
-    needs: [Prepopulate-Nix-Cache-Linux]
     steps:
       - uses: actions/checkout@v4
       - name: Setup Nix Environment
         uses: ./.github/actions/setup-nix
         with:
           tools: tests
-          cache-id: common
 
       - name: Build static executable
         run: nix-build -A postgrestStatic

.github/workflows/loadtest.yaml

@@ -26,7 +26,6 @@ jobs:
         uses: ./.github/actions/setup-nix
         with:
           tools: loadtest
-          cache-id: test-loadtest
       - uses: WyriHaximus/github-action-get-previous-tag@04e8485ecb6487243907e330d522ff60f02283ce # v1.4.0
         id: get-latest-tag
         with:
@@ -58,7 +57,6 @@ jobs:
         uses: ./.github/actions/setup-nix
         with:
           tools: loadtest
-          cache-id: test-loadtest
       - name: Run loadtest
         run: |
           postgrest-loadtest-against ${{ steps.get-latest-tag.outputs.tag }}