Update dev dependencies and bump version to 1.2.7

- Add vitest@^4.1.2, remove mocha and chai
- Upgrade jquery from ^3.7.1 to ^4.0.0
- Upgrade jsdom from ^28.1.0 to ^29.0.1
- Upgrade rollup to ^4.60.1
- Remove serialize-javascript overrides section

Author: knowledgecode