[TASK] Update flatpickr to 4.6.13

The used flatpickr library version is quite dated and was not updated
since its introduction in mid 2020. This commit updates the library to
version 4.6.13, fixing several bugs.

Additionally, the flatpickr can now be hidden by pressing the ESC key.

Changelogs: https://github.com/flatpickr/flatpickr/releases

Executed commands:

    cd Build
    nvm use
    yarn add flatpickr@^4.6.13
    grunt build

Resolves: #97837
Releases: main, 11.5
Change-Id: I4720f30447514374d638cf3d3a318e6a8e789f6d
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/75003


Tested-by: core-ci <typo3@b13.com>
Tested-by: Nikita Hovratov <nikita.h@live.de>
Tested-by: Torben Hansen <derhansen@gmail.com>
Tested-by: Simon Schaufelberger <simonschaufi+typo3@gmail.com>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Nikita Hovratov <nikita.h@live.de>
Reviewed-by: Torben Hansen <derhansen@gmail.com>
Reviewed-by: Simon Schaufelberger <simonschaufi+typo3@gmail.com>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>