[CI] Run the compile step with CARGO_INCREMENTAL=1

Author: bjorn3

.github/workflows/main.yml

@@ -57,6 +57,8 @@ jobs:
       with:
         command: rustc
         args: --release -- -Zrun_dsymutil=no
+      env:
+        CARGO_INCREMENTAL: 1
 
     - name: Test
       run: |