JSlite v1.0.1

This release fixed some issues and improves code quality:

• Updated dependent PHP version to 8.0+ in composer.json
• Fixed #1, where the static keyword was missing from the keywords regexp
• Updated github workflow with newer packages
• Removed unused variables
• Made some checks clearer
• Refactored brackets::minify() to split code blocks into smaller functions to reduce complexity
• Refactored expression::parse() to reduce cyclomatic complexity
• Improved logic in expression::isEol()
• Replaced some mb_strpos() calls with str_contains()
• Removed dead code from whitespace::minify()
• Added @property-read annotation for jslite::__get()
• Updated null check in whitespace::minify()
• Added tests