Update regex to 1.1
I just found the `aho-corasick` dependency is still `0.6.9` and then I found `regex` depends on it.
I remember there's a rewrite of `aho-corasick` at BurntSushi/aho-corasick@e8493baf54 to improve itself.
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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes do not require tests because it just updates `regex` crate
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