[9.20] fix: dev: fix the ksr two-tone test

The two-tone ksr subtest (test_ksr_twotone) depended on the dnssec-policy keys algorithm values in named.conf being entered in numerical order.  As the algorithms used in the test can be selected randomly this does not always happen. Sort the dnssec-policy keys by algorithm when adding them to the key list from named.conf.

Closes #5286

Backport of MR !10395

Merge branch 'backport-5286-ksr-two-tone-test-only-work-by-luck-9.20' into 'bind-9.20'

See merge request isc-projects/bind9!10435