Add .python-version to .gitignore (#2727)

diff --git a/.gitignore b/.gitignore
index 7db7ef9..96a5b66 100644
--- a/.gitignore
+++ b/.gitignore
@@ -39,3 +39,6 @@
 compile_commands.json
 .cache/clangd
 .clangd/
+
+# Pyenv files
+.python-version