deps: bump to regex-syntax 0.6.25
deps: bump to regex-syntax 0.6.25

rust-lang/regex,rust-lang-nursery/regex,rust-lang/regex,rust-lang/regex,rust-lang/regex,rust-lang-nursery/regex,rust-lang/regex,rust-lang-nursery/regex,rust-lang-nursery/regex,rust-lang-nursery/regex