MDL-81521 core: Update all possibly data providers to be static

Note: Some data providers could not be automatically be converted to
being static. These will be handled in a separate issue.

lib/tests/plugininfo/block_test.php

@@ -70,7 +70,7 @@ class block_test extends advanced_testcase {
         $this->assertEquals($expected, $plugininfo->is_uninstall_allowed());
     }
 
-    public function is_uninstall_allowed_provider(): array {
+    public static function is_uninstall_allowed_provider(): array {
         $plugins = block::get_enabled_plugins();
         return array_map(function ($plugin) {
             $expected = true;