tc: forbid lazy annotations on unlifted arguments (fixes #21951)
Adds additional check in GHC.Tc.TyCl.checkValidDataCon
to emit a warning for lazy annotations on arguments with unlifted types when -Wredundant-strictness-flags
is enabled. Fixes #21951 (closed).
side-note: this is my first GHC contribution, so please let me know if anything is missing/incorrect!