autopkgtest: skip all rubygems-related tests

During autopkgtest, we don't want to run the tests from the rubygems
included with ruby against the (often newer) rubygems provided by
ruby-rubygems.

Closes: #980192

Gbp-Dch: full

debian/tests/run-all

@@ -36,9 +36,16 @@ excludes="$excludes --excludes-dir=${excludedir}/autopkgtest/"
 
 run_tests=''
 for t in $tests; do
-  if ! grep -q "^$t$" "$skiplist"; then
-    run_tests="$run_tests $t"
+  if grep -q "^$t$" "$skiplist"; then
+    continue
   fi
+  case "$t" in
+    test/rubygems/*)
+      continue
+      ;;
+  esac
+
+  run_tests="$run_tests $t"
 done
 
 ruby2.7 test/runner.rb -v $excludes --name='!/memory_leak/' $run_tests

debian/tests/skiplist

@@ -11,9 +11,4 @@ test/mkmf/test_have_library.rb
 test/mkmf/base.rb
 test/mkmf/test_signedness.rb
 test/mkmf/test_constant.rb
-test/rubygems/test_gem_commands_cert_command.rb
-test/rubygems/test_gem_request.rb
-test/rubygems/test_gem_security.rb
-test/rubygems/test_gem_security_policy.rb
-test/rubygems/test_gem_security_signer.rb
-test/rubygems/test_gem_security_trust_dir.rb
+test/rdoc/test_rdoc_rubygems_hook.rb