Remove tiles outside of texture to elliminate these errors on loading the project: (#1035)

```
ERROR: Cannot create tile. The tile is outside the texture or tiles are already present in the space the tile would cover.
   at: (scene\resources\2d\tile_set.cpp:4963)
ERROR: The TileSetAtlasSource atlas has no tile at (1, 0).
   at: (scene\resources\2d\tile_set.cpp:5400)
ERROR: TileSetAtlasSource has no tile at (1, 0).
   at: (scene\resources\2d\tile_set.cpp:5348)
```