[MM-27700] storetest/channel_store: fix flaky test for search too short term (#15242)

* storetest/channel_store: fix flaky test for search too short term

* storetest/channel_store: use another stop word instead

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

store/storetest/channel_store.go

@@ -31,7 +31,8 @@ func cleanupChannels(t *testing.T, ss store.Store) {
 	list, err := ss.Channel().GetAllChannels(0, 100000, store.ChannelSearchOpts{IncludeDeleted: true})
 	require.Nilf(t, err, "error cleaning all channels: %v", err)
 	for _, channel := range *list {
-		ss.Channel().PermanentDelete(channel.Id)
+		err = ss.Channel().PermanentDelete(channel.Id)
+		assert.NoError(t, err)
 	}
 }
 
@@ -5373,8 +5374,8 @@ func testChannelStoreSearchAllChannels(t *testing.T, ss store.Store) {
 
 	o10 := model.Channel{
 		TeamId:      t1.Id,
-		DisplayName: "B10 The",
+		DisplayName: "B10 That",
-		Name:        "the",
+		Name:        "that",
 		Type:        model.CHANNEL_OPEN,
 	}
 	_, nErr = ss.Channel().Save(&o10, -1)
@@ -5440,7 +5441,7 @@ func testChannelStoreSearchAllChannels(t *testing.T, ss store.Store) {
 		{"prefix", "off-", store.ChannelSearchOpts{IncludeDeleted: false}, &model.ChannelList{&o6, &o7, &o8}, 0},
 		{"full match with dash", "off-topic", store.ChannelSearchOpts{IncludeDeleted: false}, &model.ChannelList{&o6}, 0},
 		{"town square", "town square", store.ChannelSearchOpts{IncludeDeleted: false}, &model.ChannelList{&o9}, 0},
-		{"the in name", "the", store.ChannelSearchOpts{IncludeDeleted: false}, &model.ChannelList{&o10}, 0},
+		{"that in name", "that", store.ChannelSearchOpts{IncludeDeleted: false}, &model.ChannelList{&o10}, 0},
 		{"Mobile", "Mobile", store.ChannelSearchOpts{IncludeDeleted: false}, &model.ChannelList{&o11}, 0},
 		{"search purpose", "now searchable", store.ChannelSearchOpts{IncludeDeleted: false}, &model.ChannelList{&o12}, 0},
 		{"pipe ignored", "town square |", store.ChannelSearchOpts{IncludeDeleted: false}, &model.ChannelList{&o9}, 0},