[MAINTENANCE] Fix Typo3 v11 TCA migration warning 89672

[thomaslow]

There are still TCA migration warnings in Typo3 v11, see Changelog-89672.

The 'tx_dlf_collections' TCA tables transOrigPointerField 'l18n_parent' is defined as excluded field which is no longer needed and should therefore be removed.
The 'tx_dlf_libraries' TCA tables transOrigPointerField 'l18n_parent' is defined as excluded field which is no longer needed and should therefore be removed.
The 'tx_dlf_metadata' TCA tables transOrigPointerField 'l18n_parent' is defined as excluded field which is no longer needed and should therefore be removed.
The 'tx_dlf_structures' TCA tables transOrigPointerField 'l18n_parent' is defined as excluded field which is no longer needed and should therefore be removed.

This pull request removes the respective exclude option.

There are currently problems with translations in the master branch (see #1365), which makes this difficult to test. However, it looks like this change doesn't make things worse.