Remove MutatorHandle.Parallel()

All mutators are parallel by default, remove the explicit Parallel()
calls.

Bug: 372540665
Test: all soong tests pass
Flag: EXEMPT refactor
Change-Id: I41e3a71bd13c75b7fceae91b1c4cfe678ab62df2
diff --git a/cc/cc.go b/cc/cc.go
index 3bc9635..9c514ee 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -48,10 +48,10 @@
 
 	ctx.PreDepsMutators(func(ctx android.RegisterMutatorsContext) {
 		ctx.Transition("sdk", &sdkTransitionMutator{})
-		ctx.BottomUp("llndk", llndkMutator).Parallel()
+		ctx.BottomUp("llndk", llndkMutator)
 		ctx.Transition("link", &linkageTransitionMutator{})
 		ctx.Transition("version", &versionTransitionMutator{})
-		ctx.BottomUp("begin", BeginMutator).Parallel()
+		ctx.BottomUp("begin", BeginMutator)
 	})
 
 	ctx.PostDepsMutators(func(ctx android.RegisterMutatorsContext) {
@@ -59,8 +59,8 @@
 			san.registerMutators(ctx)
 		}
 
-		ctx.BottomUp("sanitize_runtime_deps", sanitizerRuntimeDepsMutator).Parallel()
-		ctx.BottomUp("sanitize_runtime", sanitizerRuntimeMutator).Parallel()
+		ctx.BottomUp("sanitize_runtime_deps", sanitizerRuntimeDepsMutator)
+		ctx.BottomUp("sanitize_runtime", sanitizerRuntimeMutator)
 
 		ctx.Transition("fuzz", &fuzzTransitionMutator{})
 
@@ -72,8 +72,8 @@
 
 		ctx.Transition("lto", &ltoTransitionMutator{})
 
-		ctx.BottomUp("check_linktype", checkLinkTypeMutator).Parallel()
-		ctx.BottomUp("double_loadable", checkDoubleLoadableLibraries).Parallel()
+		ctx.BottomUp("check_linktype", checkLinkTypeMutator)
+		ctx.BottomUp("double_loadable", checkDoubleLoadableLibraries)
 	})
 
 	ctx.PostApexMutators(func(ctx android.RegisterMutatorsContext) {