remove frontend cors workaround since it's fixed in https://github.com/owncloud/ocis/pull/8651

[wkloucek]

Description

removes a workaround that was fixed in upstream ocis code meanwhile

Related Issue

• fix in add PATCH to default allowed CORS methods ocis#8651
• original issue CORS on /data does not work ocis#8380
• introduction of workaround work around /data CORS issues #504

Motivation and Context

see owncloud/ocis#8380

How Has This Been Tested?

• not tested

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Technical debt
• Tests only (no source changes)

Checklist:

• Code changes
• Unit tests added
• Acceptance tests added
• Documentation generated (make docs) and committed
• Documentation ticket raised:
• Documentation PR created: