automata: bump regex-syntax to latest version

Fixes #1056

Author: BurntSushi

regex-automata/Cargo.toml

@@ -85,7 +85,7 @@ internal-instrument-pikevm = ["logging", "std"]
 aho-corasick = { version = "1.0.0", optional = true, default-features = false }
 log = { version = "0.4.14", optional = true }
 memchr = { version = "2.5.0", optional = true, default-features = false }
-regex-syntax = { path = "../regex-syntax", version = "0.7.0", optional = true, default-features = false }
+regex-syntax = { path = "../regex-syntax", version = "0.7.4", optional = true, default-features = false }
 
 [dev-dependencies]
 anyhow = "1.0.69"