[TASK] Remove jQuery.proxy invocation

jQuery `$.proxy` invocation was used prior to ES6 times to have
proper `thisArg` scoping in plain JavaScript functions that were
used within jQuery events.

Since arrow functions are used (which keep their local `thisArg` scope),
corresponding `$.proxy` invocations can be removed completely.

Resolves: #94970
Releases: master
Change-Id: I2c7ec6f3a6140c98482a1c681fbae809c12c5431
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/70733


Tested-by: core-ci <typo3@b13.com>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Benjamin Franzke <bfr@qbus.de>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Benjamin Franzke <bfr@qbus.de>