Improve RegEx parser, reduce possibilities as the key for arbitrary properties (#12121)

* optimize handling of RegEx parser results

Previous:
- Copy `results`, for every subsequent result of other `patterns`
- Loop over results to filter out `undefined` values
- Loop over results to map to `clipAtBalancedParens`

Current:
- For each candidate, push the `clipAtBalancedParens(candidate)` into
  the `results`

This way we are not copying existing results, and we are also avoiding
additional loops over the entire array to filter out `undefined` values
and map to `clipAtBalancedParens`.

* do not allow `]` in the first part of arbitrary properties

```
[foo:bar]
 ─┬─
  └── This part cannot contain `]`
```

This is also a very targeted fix for when the arbitrary properties seem
to match a large piece of text, but shouldn't

* add real world tests for parsing candidate strings

* sync package-lock.json

* update changelog

CHANGELOG.md

@@ -23,6 +23,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Update types to work with `Node16` module resolution ([#12097](https://github.com/tailwindlabs/tailwindcss/pull/12097))
 - Don’t crash when important and parent selectors are equal in `@apply` ([#12112](https://github.com/tailwindlabs/tailwindcss/pull/12112))
 - Eliminate irrelevant rules when applying variants ([#12113](https://github.com/tailwindlabs/tailwindcss/pull/12113))
+- Improve RegEx parser, reduce possibilities as the key for arbitrary properties ([#12121](https://github.com/tailwindlabs/tailwindcss/pull/12121))
 
 ## [3.3.3] - 2023-07-13
 

src/lib/defaultExtractor.js

@@ -12,10 +12,12 @@ export function defaultExtractor(context) {
     let results = []
 
     for (let pattern of patterns) {
-      results = [...results, ...(content.match(pattern) ?? [])]
+      for (let result of content.match(pattern) ?? []) {
+        results.push(clipAtBalancedParens(result))
+      }
     }
 
-    return results.filter((v) => v !== undefined).map(clipAtBalancedParens)
+    return results
   }
 }
 
@@ -34,7 +36,7 @@ function* buildRegExps(context) {
     // This is a targeted fix to continue to allow theme()
     // with square brackets to work in arbitrary properties
     // while fixing a problem with the regex matching too much
-    /\[[^\s:'"`]+:[^\s]+?\[[^\s]+\][^\s]+?\]/,
+    /\[[^\s:'"`\]]+:[^\s]+?\[[^\s]+\][^\s]+?\]/,
 
     // Utilities
     regex.pattern([