[style] bump yapf version to 0.31.0 (#6434)
diff --git a/script/bootstrap b/script/bootstrap
index 1fcd832..3af33a3 100755
--- a/script/bootstrap
+++ b/script/bootstrap
@@ -41,7 +41,7 @@
sudo apt-get --no-install-recommends install -y clang-format-9 clang-tidy-9 || echo 'WARNING: could not install clang-format-9 and clang-tidy-9, which is useful if you plan to contribute C/C++ code to the OpenThread project.'
# add yapf for pretty
- python3 -m pip install yapf==0.29.0 || echo 'WARNING: could not install yapf, which is useful if you plan to contribute python code to the OpenThread project.'
+ python3 -m pip install yapf==0.31.0 || echo 'WARNING: could not install yapf, which is useful if you plan to contribute python code to the OpenThread project.'
# add mdv for local size report
python3 -m pip install mdv || echo 'WARNING: could not install mdv, which is required to post markdown size report for OpenThread.'