[AArch64][NFC] Fix label checks on ZCM tests (#173482)
Previous checks were dead code. Now we share single `ALL-LABEL` checks
by all run lines. Note: the regex is currently needed for
`--match-full-lines` which is needed by itself because the previous
versions of these tests suffered from false positives due to partial
matching: https://github.com/llvm/llvm-project/pull/143680.
