Instances created from some Noto VFs fail remove overlaps

```
fonttools varLib.instancer ofl/notosansethiopic/NotoSansEthiopic\[wdth\,wght\].ttf wdth=100 wght=800 --remove-overlaps

Restricting axes: {'wdth': 100.0, 'wght': 800.0}
Loading variable font
Normalized limits: {'wght': 0.78997802734375, 'wdth': 0.0}
Instantiating glyf/gvar tables
Dropping HVAR table
Instantiating GDEF and GPOS tables
Dropping avar table
Dropping fvar table
Pruning name table
Removing overlaps from glyf table
Traceback (most recent call last):
File "/tmp/venv/bin/fonttools", line 8, in
sys.exit(main())
File "/private/tmp/venv/lib/python3.9/site-packages/fontTools/__main__.py", line 30, in main
runpy.run_module(mod, run_name='__main__')
File "/usr/local/Cellar/python@3.9/3.9.4/Frameworks/Python.framework/Versions/3.9/lib/python3.9/runpy.py", line 213, in run_module
return _run_code(code, {}, init_globals, run_name, mod_spec)
File "/usr/local/Cellar/python@3.9/3.9.4/Frameworks/Python.framework/Versions/3.9/lib/python3.9/runpy.py", line 87, in _run_code
exec(code, run_globals)
File "/private/tmp/venv/lib/python3.9/site-packages/fontTools/varLib/instancer/__main__.py", line 5, in
sys.exit(main())
File "/private/tmp/venv/lib/python3.9/site-packages/fontTools/varLib/instancer/__init__.py", line 1408, in main
instantiateVariableFont(
File "/private/tmp/venv/lib/python3.9/site-packages/fontTools/varLib/instancer/__init__.py", line 1250, in instantiateVariableFont
removeOverlaps(varfont)
File "/private/tmp/venv/lib/python3.9/site-packages/fontTools/ttLib/removeOverlaps.py", line 162, in removeOverlaps
if removeTTGlyphOverlaps(
File "/private/tmp/venv/lib/python3.9/site-packages/fontTools/ttLib/removeOverlaps.py", line 96, in removeTTGlyphOverlaps
path2 = pathops.simplify(path, clockwise=path.clockwise)
File "src/python/pathops/_pathops.pyx", line 1476, in pathops._pathops.simplify
File "src/python/pathops/_pathops.pyx", line 1487, in pathops._pathops.simplify
pathops._pathops.PathOpsError: operation did not succeed
```