internal/rosa/cmake: implicit CMAKE_BUILD_TYPE

Lack of this behaviour is a holdover from when the helper was first split from the (now removed) LLVM helper.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/rosa/llvm.go

@@ -10,8 +10,6 @@ import (
 
 func (t Toolchain) newLLVM() (pkg.Artifact, string) {
 	cache := []KV{
-		{"CMAKE_BUILD_TYPE", "Release"},
-
 		{"ENABLE_LINKER_BUILD_ID", "ON"},
 		{"COMPILER_RT_USE_BUILTINS_LIBRARY", "ON"},
 		{"COMPILER_RT_DEFAULT_TARGET_ONLY", "ON"},