Simplify workflows: keep only CI and simple Ubuntu release

.github/workflows/ci.yml

@@ -44,8 +44,12 @@ jobs:
           purge-created: 0
           purge-primary-key: never
           gc-max-store-size: 5G
-      - name: Save flake attributes from garbage collection
-        run: nix profile install .#saveFromGC
+      - name: Install cross-compilation toolchain
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y gcc-x86-64-linux-gnu g++-x86-64-linux-gnu
+      - name: Clear Nix cache to force rebuild
+        run: nix-collect-garbage -d
 
   check:
     name: Run checks
@@ -70,6 +74,12 @@ jobs:
           purge-created: 0
           purge-primary-key: never
           gc-max-store-size: 5G
+      - name: Install cross-compilation toolchain
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y gcc-x86-64-linux-gnu g++-x86-64-linux-gnu
+      - name: Clear Nix cache to force rebuild
+        run: nix-collect-garbage -d
       - name: Run checks
         run: nix flake check
 
@@ -96,6 +106,12 @@ jobs:
           purge-created: 0
           purge-primary-key: never
           gc-max-store-size: 5G
+      - name: Install cross-compilation toolchain
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y gcc-x86-64-linux-gnu g++-x86-64-linux-gnu
+      - name: Clear Nix cache to force rebuild
+        run: nix-collect-garbage -d
       - name: Build
         run: nix build .#
 
@@ -122,24 +138,11 @@ jobs:
           purge-created: 0
           purge-primary-key: never
           gc-max-store-size: 5G
+      - name: Install cross-compilation toolchain
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y gcc-x86-64-linux-gnu g++-x86-64-linux-gnu
+      - name: Clear Nix cache to force rebuild
+        run: nix-collect-garbage -d
       - name: Run Tests
         run: 'nix develop --command bash -c "cargo test"'
-
-  coverage:
-    name: Run Coverage
-    runs-on: ubuntu-24.04
-    permissions:
-      contents: read
-    steps:
-      - uses: actions/checkout@v5
-        with:
-          ref: ${{ github.event.pull_request.head.sha }}
-      - uses: taiki-e/install-action@cargo-llvm-cov
-      - name: Generate code coverage
-        run: cargo llvm-cov --all-features --workspace --codecov --output-path codecov.json
-      - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@v5
-        with:
-          token: ${{ secrets.CODECOV_TOKEN }} # not required for public repos
-          files: codecov.json
-          fail_ci_if_error: true