Remove legacy date-based code blocks

[ManupaKDU]

Removed deprecated backward compatibility blocks in BillSearch.java and PatientReportController.java that handled encryptedExpiary.

These legacy blocks were marked with "TODO: Remove this legacy block after 2026-07-09." and provided 1-month TTL compatibility for old links sent prior to HMAC migration. Since this date has passed, these blocks are no longer necessary and have been removed.

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PR created automatically by Jules for task 11070097839040137615 started by @manupawickramasinghe

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