chore: update copyright year from 2020-2023 to 2020-2024

[TheCodby]

Summary of change

Updated the copyright notice across the project from 2020-2023 to 2020-2024 to keep project information up-to-date.

Related issues

No specific issues linked to this update.

Test Plan

no functional testing is required

Documentation changes

not required

Checklist for important updates

• Changelog has been updated
  • If there are any db schema changes, mention those changes clearly
• coreDriverInterfaceSupported.json file has been updated (if needed)
• pluginInterfaceSupported.json file has been updated (if needed)
• Changes to the version if needed
  • In build.gradle
• If added a new paid feature, edit the getPaidFeatureStats function in FeatureFlag.java file
• Had installed and ran the pre-commit hook
• If there are new dependencies that have been added in build.gradle, please make sure to add them
  in implementationDependencies.json.
• Update function getValidFields in io/supertokens/config/CoreConfig.java if new aliases were added for any core
  config (similar to the access_token_signing_key_update_interval config alias).
• Issue this PR against the latest non released version branch.
  • To know which one it is, run find the latest released tag (git tag) in the format vX.Y.Z, and then find the
    latest branch (git branch --all) whose X.Y is greater than the latest released tag.
  • If no such branch exists, then create one from the latest released branch.
• If added a foreign key constraint on app_id_to_user_id table, make sure to delete from this table when deleting
  the user as well if deleteUserIdMappingToo is false.

Remaining TODOs for this PR

None