Move checks into a separate YAML file

.github/workflows/build.yaml

@@ -5,20 +5,6 @@ on:
   workflow_call:
 
 jobs:
-  checks:
-    runs-on: ubuntu-22.04
-    steps:
-      - uses: actions/checkout@v3
-
-      - uses: DeterminateSystems/nix-installer-action-cache@main
-
-      - name: Check Rust formatting
-        run: nix develop --command cargo fmt --check
-      
-      - name: Clippy
-        run: nix develop --command cargo clippy
-
-
   build-artifacts-X64-macOS:
     runs-on: macos-12
     steps:

.github/workflows/checks.yaml

@@ -0,0 +1,20 @@
+name: Rust checks
+
+on:
+  pull_request:
+  push:
+    branches: [main]
+
+jobs:
+  checks:
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v3
+
+      - uses: DeterminateSystems/nix-installer-action-cache@main
+
+      - name: Check Rust formatting
+        run: nix develop --command cargo fmt --check
+      
+      - name: Clippy
+        run: nix develop --command cargo clippy