fix(swift) ensure keyword attributes highlight correctly

[bradleymackey]

Changes

• Prevent keyword attributes from greedily matching non-keyword attributes
• Lookahead to either a trailing whitespace character or an opening paren to ensure matches are exact for the keywords.
• Prevents issues like @objcMembers being prematurely highlighted as @objc only.
• Also prevents issues where meta attributes may have the same prefix as a keyword

Checklist

• Added markup tests, or they don't apply here because...
• Updated the changelog at CHANGES.md

[github-actions]

Build Size Report

Changes to minified artifacts in /build, after gzip compression.

5 files changed

Total change +32 B

View Changes

file	base	pr	diff
es/core.min.js	8.17 KB	8.17 KB	+2 B
es/highlight.min.js	8.17 KB	8.17 KB	+2 B
es/languages/swift.min.js	3.54 KB	3.55 KB	+13 B
highlight.min.js	8.2 KB	8.21 KB	+2 B
languages/swift.min.js	3.54 KB	3.56 KB	+13 B

[github-actions]

Build Size Report

Changes to minified artifacts in /build, after gzip compression.

5 files changed

Total change +23 B

View Changes

file	base	pr	diff
es/core.min.js	8.17 KB	8.17 KB	-1 B
es/highlight.min.js	8.17 KB	8.17 KB	-1 B
es/languages/swift.min.js	3.54 KB	3.55 KB	+13 B
highlight.min.js	8.21 KB	8.21 KB	-1 B
languages/swift.min.js	3.55 KB	3.56 KB	+13 B

[github-actions]

Build Size Report

Changes to minified artifacts in /build, after gzip compression.

2 files changed

Total change +26 B

View Changes

file	base	pr	diff
es/languages/swift.min.js	3.54 KB	3.55 KB	+13 B
languages/swift.min.js	3.55 KB	3.56 KB	+13 B