chore(deps): replace eslint-plugin-square

[MikeMcC399]

• contributes to resolution of Migrate to ESLint flat config for CI tests #529
• implements recommendation from Migrate to ESLint flat config for CI tests #529 (comment) to remove eslint-plugin-square

Issue

1. eslint-plugin-square says "It is generally not recommended for public usage outside of Square.".
2. eslint-plugin-square offers no flat config. flat configuration is however the standard for ESLint v9 and later, and so remaining with this plugin would prevent migration.

Change

• Uninstall eslint-plugin-square@24.0.0 and remove plugin:square/typescript from the ESLint configuration
• Separately install the following as devDependencies, which were previously pulled in by eslint-plugin-square@24.0.0
  • eslint-plugin-import@^2.26.0
  • eslint-plugin-unicorn@^45.0.2
• Modify .eslintrc.cjs accordingly.