fix: avoid collisions between FuzzRemoveRules fuzzers

[egibs]

Addresses:

Run go test -parallel=1 -timeout 0 -fuzz="FuzzRemoveRules" -fuzztime="${FUZZ_TIME}" "./pkg/compile/"
testing: will not fuzz, -fuzz matches more than one fuzz test: [FuzzRemoveRules FuzzRemoveRulesRegex]
FAIL
exit status 1
FAIL	github.com/chainguard-dev/malcontent/pkg/compile	57.211s
Error: Process completed with exit code 1.

FuzzRemoveRulesRegex worked because it was a unique test but this failed because it matched more than one fuzzer. This PR updates the name to be unique and avoids future collisions by anchoring future patterns like we do in the Makefile.

[stevebeattie]

Nice fix, thanks!