Add old innovation releases to exclusion list.

Author: desrosj

.github/workflows/install-testing.yml

@@ -92,6 +92,8 @@ jobs:
             db-version: '8.4'
           # Only test the latest innovation release.
           - db-version: '9.0'
+          - db-version: '9.1'
+          - db-version: '9.2'
           # MySQL 9.0+ will not work on PHP 7.2 & 7.3. See https://core.trac.wordpress.org/ticket/61218.
           - php: '7.2'
             db-version: '9.3'