ci: cache race-enabled Go build artifacts (#5137)

Author: Frozen

.github/cache-keys/go-checker-race-v1

@@ -0,0 +1 @@
+go-checker race cache namespace v1

.github/workflows/ci-pr.yaml

@@ -40,8 +40,7 @@ jobs:
           path: go/src/github.com/harmony-one/harmony
           persist-credentials: false
 
-      - &setup-go
-        name: Set up Go
+      - name: Set up Go
         uses: actions/setup-go@924ae3a1cded613372ab5595356fb5720e22ba16 #v6.5.0
         with:
           go-version: '1.24.2'
@@ -70,7 +69,16 @@ jobs:
     strategy: *arch-matrix
     steps:
       - *checkout-harmony
-      - *setup-go
+      - name: Set up Go with race cache
+        uses: actions/setup-go@924ae3a1cded613372ab5595356fb5720e22ba16 #v6.5.0
+        with:
+          go-version: '1.24.2'
+          # Keep race-enabled build artifacts separate from the regular build cache.
+          # actions/setup-go already separates cache keys by runner architecture.
+          # Bump the marker file when the race cache strategy changes.
+          cache-dependency-path: |
+            go/src/github.com/harmony-one/harmony/go.sum
+            go/src/github.com/harmony-one/harmony/.github/cache-keys/go-checker-race-v1
       - name: Install tools
         run: |
           go install golang.org/x/tools/cmd/goimports@v0.30.0