Update to 9.21.3 (#2331674)

New Features:

• Add separate query counters for new protocols. [GL #598]
• Implement RFC 9567: EDNS Report-Channel option.[GL #3659]
• Add detailed debugging of update-policy rule matching. [GL #4751]
• Enable runtime selection of FIPS mode in dig and delv. [GL #5046]

Removed Features:

• Move contributed DLZ modules into a separate repository. DLZ modules should not be used except in testing. [GL #4865]
• Remove RBTDB implementation. [GL #5027]

Features Changes:

• dnssec-ksr now supports KSK rollovers. [GL #4697] [GL #4705]
• Add none parameter to query-source and query-source-v6 to disable IPv4 or IPv6 upstream queries but allow listening to queries from clients on IPv4 or IPv6.
• Print RFC 7314: EXPIRE option in transfer summary. [GL #5013]
• Add missing EDNS option mnemonics to dig.
• Add new logging module for crypto errors in libisc.
• Emit more helpful log messages for exceeding max-records-per-type.
• Harden key management when key files have become unavailable.
• Reduce memory footprint by optimizing commonly-used data structures. [GL #5022]

And multiple bug fixes.

https://downloads.isc.org/isc/bind9/9.21.3/doc/arm/html/notes.html#notes-for-bind-9-21-3