[ondrejmirtes]

Continues #6906. --fix now also fixes ignore.unmatched and too high ignore.count in NEON config files, like phpstan-baseline.neon, and --fix-ignored cleans up the ignores it makes stale.

PHPStan\Neon\Printer
A format-preserving printer for nette/neon syntax trees, modelled on the printers of nikic/php-parser and phpstan/phpdoc-parser:

• A tree is changed by replacing nodes with clones that keep the token positions of the original nodes. Unchanged code is printed as written, with comments and whitespace. Nodes created with new are printed fresh.
• List items are compared with phpdoc-parser's Differ, so items can be removed, added and reordered. The comment at the end of an item's line and the comment lines right above an item belong to the item. Inline arrays and entity attributes keep their separators. Removing every entry prints ignoreErrors: [].
• printChanges() returns only the changed byte ranges. Unchanged code is referred to by token ranges and is not copied, so the cost depends on the size of the change, not of the file.
• nette/neon strips \r. The fixer puts CRLF back when every line break had it, and does not fix files with mixed line endings.

nette/neon stays at 3.3.4. Its parser and syntax tree are @internal, so one scoped ignoreErrors entry in build/phpstan.neon covers src/Neon, the fixer and the printer tests. nette/neon 4.0, which made the API public (nette/neon#52), requires PHP 8.4.

Performance
Measured on the WordPress level 10 NEON baseline (30,989 entries, 6.2 MB), with 1,240 entries that no longer match and 620 counts that are too high. Printing the whole file for each fix took 53.9 s in total. With printChanges() it takes 8.4 s, including a one-time 1.9 s parse, about 2 ms per fix. All 1,870 errors are fixed in one round, and the result equals the expected baseline byte for byte.

Removing neighbouring items
A removal edit starts at the end of the previous item, so the edits for two neighbouring items touch the same line and Patcher puts the second one into the next round. A list like messages: is therefore never left empty, like with the PHP fixer.

--fix-ignored
Fixing an ignored error leaves behind the ignore that matched it: an unmatched ignoreErrors entry, a count that is too high, or an unmatched @phpstan-ignore comment. These are reported errors, so --fix-ignored on its own left them in place and the next run failed. Later rounds now also fix fixable ignore.* errors in the files that earlier rounds changed. Stale ignores in other files were already there and are left alone. The main process passes the changed files to each round worker with an internal --fixed-ignored-in option.

Tests

• tests/PHPStan/Neon/PrinterTest.php: each case checks the exact output, that it decodes to the same value, and that printChanges() gives the same result.
• IgnoreErrorsConfigFixerTest: NEON cases for entries with comments, list items, lowering a count, %%, CRLF, duplicate entries that aren't fixed, and neighbouring removals.
• e2e/fix-baseline now also fixes a NEON baseline.
• New e2e/fix-ignored-entries covers a PHP baseline entry, a NEON count and an inline comment, plus a stale entry in an untouched file that must stay.
• e2e/fix: its ignoreErrors entry moved into a copied ignore.neon, because --fix-ignored now removes it.