[v25.2.x] deps: update libxml2 from 2.14.5 to 2.14.6

[tyson-redpanda]

Backport of PR #29423

FIXES=CORE-15341

[vbotbuildovich]

Retry command for Build#79782

please wait until all jobs are finished before running the slash command

/ci-repeat 1
skip-redpanda-build
skip-units
skip-rebase
tests/rptest/tests/random_node_operations_test.py::RandomNodeOperationsTest.test_node_operations@{"cloud_storage_type":2,"compaction_mode":"sliding_window","enable_failures":false,"mixed_versions":true,"with_iceberg":false}

[vbotbuildovich]

CI test results

test results on build#79782

test_class	test_method	test_arguments	test_kind	job_url	test_status	passed	reason	test_history
PartitionMovementUpgradeTest	test_basic_upgrade	null	integration	https://buildkite.com/redpanda/redpanda/builds/79782#019c0585-b44e-47d9-b749-de8fe3560a5e	FLAKY	19/21	Test PASSES after retries.No significant increase in flaky rate(baseline=0.0238, p0=0.3824, reject_threshold=0.0100. adj_baseline=0.1000, p1=0.3917, trust_threshold=0.5000)	https://redpanda.metabaseapp.com/dashboard/87-tests?tab=142-dt-individual-test-history&test_class=PartitionMovementUpgradeTest&test_method=test_basic_upgrade
PartitionMovementUpgradeTest	test_basic_upgrade	null	integration	https://buildkite.com/redpanda/redpanda/builds/79782#019c0586-626e-4745-bb49-7073cfca1d23	FLAKY	10/11	Test PASSES after retries.No significant increase in flaky rate(baseline=0.0238, 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=PartitionMovementUpgradeTest&test_method=test_basic_upgrade
RandomNodeOperationsTest	test_node_operations	{"cloud_storage_type": 2, "compaction_mode": "sliding_window", "enable_failures": false, "mixed_versions": true, "with_iceberg": false}	integration	https://buildkite.com/redpanda/redpanda/builds/79782#019c0585-b456-4819-9f6f-7c6b7754533b	FLAKY	27/31	Test FAILS after retries.Significant increase in flaky rate(baseline=0.0112, p0=0.0045, reject_threshold=0.0100)	https://redpanda.metabaseapp.com/dashboard/87-tests?tab=142-dt-individual-test-history&test_class=RandomNodeOperationsTest&test_method=test_node_operations