[v25.3.x] build/deps: upgrade krb5 to 1.22.2

[tyson-redpanda]

Upgrades krb5 from 1.21.3 to 1.22.2 on the v25.3.x branch to address CVE-2026-40355 and CVE-2026-40356 (NegoEx parsing vulnerabilities). The memory leak fixes previously applied via 0001 patch are included in 1.22.x upstream, so that patch is dropped. The NegoEx CVE patches still apply cleanly to 1.22.2 and are retained.

Backport of PR #30628

Backports Required

• none - not a bug fix
• none - this is a backport
• none - issue does not exist in previous branches
• none - papercut/not impactful enough to backport
• v25.3.x
• v25.2.x
• v25.1.x

Release Notes

Bug Fixes

• Upgrade krb5 to 1.22.2 to address CVE-2026-40355 and CVE-2026-40356 (NegoEx parsing vulnerabilities).

FIXES=CORE-16460
FIXES=CORE-16461

[vbotbuildovich]

CI test results

test results on build#86153

test_status	test_class	test_method	test_arguments	test_kind	job_url	passed	reason	test_history
FLAKY(PASS)	PartitionReassignmentsTest	test_reassignments_cancel	null	integration	https://buildkite.com/redpanda/redpanda/builds/86153#019ef501-0eb3-45c0-8292-ad199a74e15e	9/11	Test PASSES after retries.No significant increase in flaky rate(baseline=0.0625, p0=0.4755, reject_threshold=0.0100. adj_baseline=0.1760, p1=0.4524, trust_threshold=0.5000)	https://redpanda.metabaseapp.com/dashboard/87-tests?tab=142-dt-individual-test-history&test_class=PartitionReassignmentsTest&test_method=test_reassignments_cancel
FLAKY(PASS)	TxAtomicProduceConsumeTest	test_basic_tx_consumer_transform_produce	{"with_failures": true}	integration	https://buildkite.com/redpanda/redpanda/builds/86153#019ef503-f6b6-4352-b960-056ec495e9d5	10/11	Test PASSES after retries.No significant increase in flaky rate(baseline=0.0000, p0=1.0000, reject_threshold=0.0100. adj_baseline=0.1000, p1=0.3487, trust_threshold=0.5000)	https://redpanda.metabaseapp.com/dashboard/87-tests?tab=142-dt-individual-test-history&test_class=TxAtomicProduceConsumeTest&test_method=test_basic_tx_consumer_transform_produce