Backport fix for #34754 (disable Task04115LowercaseIdentifierUrls) to 21.06

Description

Task04115LowercaseIdentifierUrls lowercases parent_path and asset_name in the
identifier table when upgrading from any pre-4.1.0 database (db_version < 4115).
This was disabled in #34754 (PR #34803, commit 3d130b5) and released in 26.02.27,
but 21.06 is still affected.

A customer migrating 2.5.6 → 3.7.2 → 21.06 → (Oracle→PostgreSQL) → target version
needs asset identifiers/URLs to preserve original casing while passing through 21.06.
Coming from 3.7.2 (db_version 3605), the task executes on their path. They have
confirmed further upgrade runs from the source for data alignment before cutover,
so an official 21.06 build is required.

The backport is the same one-line change as 3d130b5: forceRun() returns false
in Task04115LowercaseIdentifierUrls.java. The 21.06 StartupTasksExecutor still
records 4115 in db_version after skipping, so the upgrade sequence stays consistent.

Acceptance Criteria

Official 21.06 patch build published with Task04115LowercaseIdentifierUrls disabled
original filenames/identifier casing preserved when upgrading from pre-4.1 versions.

Priority

High

Additional Context

Parent issue: #34754 · Fix commit: 3d130b5 · Released in: 26.02.27

Ticket: https://helpdesk.dotcms.com/a/tickets/38327
(Original issue: https://helpdesk.dotcms.com/a/tickets/35549)

Start with Task04115LowercaseIdentifierUrls.java in the 21.06 code and compare its forceRun() behavior with the referenced fix commit 3d130b5. Confirm the skipped task still records 4115 in db_version, then verify an upgrade from a pre-4.1 database preserves original asset identifier casing and that an official 21.06 patch build can be produced.