vladbogo: one idea of adding spider to default suites is by
applying the following patch as an extra f_quick_build step in
common_factories.py, but it could be fragile if mariadb-test-run.pl
changes

diff --git a/mysql-test/mariadb-test-run.pl b/mysql-test/mariadb-test-run.pl

index df860621423..443dc8aa177 100755

--- a/mysql-test/mariadb-test-run.pl

+++ b/mysql-test/mariadb-test-run.pl

@@ -217,6 +217,12 @@ my @DEFAULT_SUITES= qw(

     versioning-

     period-

     sysschema-

+    spider-

+    spider/bg-

+    spider/bugfix-

+    spider/feature-

+    spider/regression/e1121-

+    spider/regression/e112122-

   );

 my $opt_suites;

Don't do that. If non-default tests need to be run, run them as a separate MTR step instead.
However, most (or all) of these suites are already run by default, as you can see for example in the standard test runs in the old buildbot. mysql-test-run.pl defines the hardcoded default suites. Other suites can define themselves as default via the corresponding suite.pm, and spider does that.
If they aren't run in the new buildbot, it must be not because they are not default, but because the buildbot runs an explicit subset of tests.