pin meson==0.55.3 to try fix PermissionError on windows
pin meson==0.55.3 to try fix PermissionError on windows

with latest meson 0.56, Appveyor CI sometimes fails with

https://ci.appveyor.com/project/googlefonts/ots-python/builds/36989591/job/6e2orcxjbfyy6j3b#L184

sometimes it passes.. I have no idea.

googlefonts/ots-python,googlefonts/ots-python