fix(ci): prevent race test OOM and fix cross-platform check (#33)

- Add -count=1 -timeout=5m to race tests to prevent unbounded runs
- Set GOGC=50 in CI to reduce memory pressure under the race detector
- Change cross-platform step from go test (requires runner) to go vet
  (compile-only check)

Author: xe-nvdk

.github/workflows/build.yml

@@ -25,3 +25,5 @@ jobs:
 
       - name: Test
         run: make test
+        env:
+          GOGC: 50

Makefile

@@ -1,6 +1,6 @@
 test:
 	go test ./...
-	go test ./... -short -race
+	go test ./... -short -race -count=1 -timeout=5m
 	go test ./... -run=NONE -bench=. -benchmem
-	env GOOS=linux GOARCH=386 go test ./...
+	env GOOS=linux GOARCH=386 go vet ./...
 	go vet