Fix misspellings and enable misspell on ci (#16285)

Co-authored-by: Ben Schumacher <ben.schumacher@mattermost.com>

config/feature_flags.go

@@ -56,7 +56,7 @@ func NewFeatureFlagSynchronizer(params FeatureFlagSyncParams) (*FeatureFlagSynch
 // ensureReady blocks until the syncronizer is ready to update feature flag values
 func (f *FeatureFlagSynchronizer) EnsureReady() error {
 	if err := f.client.BlockUntilReady(10); err != nil {
-		return errors.Wrap(err, "split.io client could not initalize")
+		return errors.Wrap(err, "split.io client could not initialize")
 	}
 
 	return nil