Use parentheses for merge+diff vertex names.
Use parentheses for merge+diff vertex names.

This is easier to read than quotes, which result in lots of escaping in
progress output.

Signed-off-by: Erik Sipsma <c195b508e6f0c57aeafdb5e96947e2b79e6a4b40@sipsma.dev>

tonistiigi/buildkit_poc,tonistiigi/buildkit_poc