test: use typed atomics in test files (#25071)

Use typed atomics (atomic.Int64, atomic.Int32, etc.) in test files to prevent
mixing atomic and non-atomic access on the same value, guarantee 64-bit
alignment on 32-bit platforms, and provide a cleaner API.

cli/agent_test.go

@@ -122,8 +122,8 @@ func TestWorkspaceAgent(t *testing.T) {
 		var (
 			admin              = coderdtest.CreateFirstUser(t, client)
 			member, memberUser = coderdtest.CreateAnotherUser(t, client, admin.OrganizationID)
-			called             int64
-			derpCalled         int64
+			called             atomic.Int64
+			derpCalled         atomic.Int64
 		)
 
 		setHandler(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
@@ -133,9 +133,9 @@ func TestWorkspaceAgent(t *testing.T) {
 				assert.Equal(t, "very-wow-"+client.URL.String(), r.Header.Get("X-Process-Testing"))
 				assert.Equal(t, "more-wow", r.Header.Get("X-Process-Testing2"))
 				if strings.HasPrefix(r.URL.Path, "/derp") {
-					atomic.AddInt64(&derpCalled, 1)
+					derpCalled.Add(1)
 				} else {
-					atomic.AddInt64(&called, 1)
+					called.Add(1)
 				}
 			}
 			coderAPI.RootHandler.ServeHTTP(w, r)
@@ -178,8 +178,8 @@ func TestWorkspaceAgent(t *testing.T) {
 		err := clientInv.WithContext(ctx).Run()
 		require.NoError(t, err)
 
-		require.Greater(t, atomic.LoadInt64(&called), int64(0), "expected coderd to be reached with custom headers")
-		require.Greater(t, atomic.LoadInt64(&derpCalled), int64(0), "expected /derp to be called with custom headers")
+		require.Greater(t, called.Load(), int64(0), "expected coderd to be reached with custom headers")
+		require.Greater(t, derpCalled.Load(), int64(0), "expected /derp to be called with custom headers")
 	})
 
 	t.Run("DisabledServers", func(t *testing.T) {