Bump minimum regex version to 1.5.5
Per [RUSTSEC-2022-0013](https://rustsec.org/advisories/RUSTSEC-2022-0013), `regex` version `<1.5.5` is susceptible to DOS. While it doesn't look like `sccache` parses untrusted regular expressions and I assume its dependencies don't either, this change should be a no-op for functionality.
@@ -56,7 +56,7 @@ number_prefix = "0.4"
openssl = { version = "0.10", optional = true }
percent-encoding = { version = "2", optional = true }
rand = "0.8.4"
-regex = "1"
+regex = "1.5.5"
reqwest = { version = "0.11", features = ["json", "blocking", "stream"], optional = true }
retry = "1"
ring = { version = "0.16", optional = true, features = ["std"] }
