Allow warnings when running CI on release branches (boa-dev#3990)

Author: jedel1043

.github/workflows/release.yml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 60
     env:
-      RUSTFLAGS: -D warnings
+      RUSTFLAGS: ${{ github.ref == 'refs/heads/main' && '-D warnings' || '' }}
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4

.github/workflows/rust.yml

@@ -13,13 +13,14 @@ on:
     types: [checks_requested]
 
 env:
-  RUSTFLAGS: -Dwarnings
+  RUSTFLAGS: ${{ github.ref == 'refs/heads/main' && '-D warnings' || '' }}
 
 jobs:
   coverage:
     name: Coverage
     runs-on: ubuntu-latest
     timeout-minutes: 60
+    if: github.ref == 'refs/heads/main'
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
@@ -151,7 +152,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 60
     env:
-      RUSTDOCFLAGS: -D warnings
+      RUSTDOCFLAGS: ${{ github.ref == 'refs/heads/main' && '-D warnings' || '' }}
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4

.github/workflows/webassembly.yml

@@ -29,7 +29,7 @@ jobs:
     timeout-minutes: 60
     env:
       WASM_PACK_PATH: ~/.cargo/bin/wasm-pack
-      RUSTFLAGS: -D warnings
+      RUSTFLAGS: ${{ github.ref == 'refs/heads/main' && '-Dwarnings' || '' }}
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4