[TASK] Remove FlexForm event listeners (#218)

These examples for event listeners do not really make sense:
- The identifiers are referring to "form-framework"
- A data structure is referring to "myext"
- Table "tx_myext_sometable" is unknown
- Type "some_other_type" is unknown

Therefore, they are removed.

Releases: main, 12.4

Co-authored-by: Chris Müller <2566282+brotkrueml@users.noreply.github.com>

Configuration/Services.yaml

@@ -17,21 +17,6 @@ services:
       - name: event.listener
         identifier: 'txExampleCheckExternalLinksToLocalPages'
 
-  T3docs\Examples\EventListener\Core\Configuration\FlexFormParsingModifyEventListener:
-    tags:
-      - name: event.listener
-        identifier: 'form-framework/set-data-structure'
-        method: 'setDataStructure'
-      - name: event.listener
-        identifier: 'form-framework/modify-data-structure'
-        method: 'modifyDataStructure'
-      - name: event.listener
-        identifier: 'form-framework/set-data-structure-identifier'
-        method: 'setDataStructureIdentifier'
-      - name: event.listener
-        identifier: 'form-framework/modify-data-structure-identifier'
-        method: 'modifyDataStructureIdentifier'
-
   T3docs\Examples\Command\DoSomethingCommand:
     tags:
       - name: console.command