[TASK] Implement `@typescript-eslint/restrict-plus-operands` rule

The eslint configuration now takes the rule
`@typescript-eslint/restrict-plus-operands` [1] into account,
prohibiting merging of type-incompatible operands.

[1] https://typescript-eslint.io/rules/restrict-plus-operands

Resolves: #103378
Releases: main, 12.4
Change-Id: I267272e4f384cbcabc245cd85ea493886134b026
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/83439


Reviewed-by: Garvin Hicking <gh@faktor-e.de>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Garvin Hicking <gh@faktor-e.de>
Tested-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Andreas Kienast <a.fernandez@scripting-base.de>
Tested-by: Andreas Kienast <a.fernandez@scripting-base.de>