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/zstd.go

@@ -19,9 +19,6 @@ func (t Toolchain) newZstd() (pkg.Artifact, string) {
 		Chmod:    true,
 	}, &CMakeHelper{
 		Append: []string{"build", "cmake"},
-		Cache: []KV{
-			{"CMAKE_BUILD_TYPE", "Release"},
-		},
 		Test: `
 make -C /usr/src/zstd/tests datagen
 ZSTD_BIN=/cure/programs/zstd /usr/src/zstd/tests/playTests.sh