finance/pear_Payment_DTA: Deprecate and set expiration date

Upstream released the last version 1.4.3 in June 2012 and the PEAR
channel itself has seen no activity since. The DTAUS file format the
package produces has been superseded by SEPA and is no longer accepted
by German banks, so the port has no remaining use case.

MFH: 2026Q3
Sponsored by: Netzkommune GmbH

(cherry picked from commit 2c6b0c1c1c1e78952cf01a97a0bd1ee77492dfe1)