The Build/composer/ directory (recently added in 95046 )
contains all core files (symlinked) once `composer install`
has been executed, that means both typoscript and typescript
files that end with .ts. This leads to compilation errors.

These files must actually be ignored by `tsc` during `grunt build`.
and should not be compiled at all (wasted ressources).

While at it we also fix the tsconfig.json to include
a trailing newline, in order to comply to our coding guidelines.

Releases: master
Resolves: #95046
Related: #94996
Change-Id: Ic8d4a4af1004e0f8c9ae5c4832b54e1018055ec2
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/70830


Tested-by: core-ci <typo3@b13.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Tymoteusz Motylewski <t.motylewski@gmail.com>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Tymoteusz Motylewski <t.motylewski@gmail.com>