add venv and .venv to the .gitignore

.gitignore

@@ -63,6 +63,10 @@ tests/data/*.translation
 # Binutils tmp linker output of the form "stXXXXXX" where "X" is alphanumeric
 st[A-Za-z0-9][A-Za-z0-9][A-Za-z0-9][A-Za-z0-9][A-Za-z0-9][A-Za-z0-9]
 
+# Python development
+.venv
+venv
+
 # Python generated
 __pycache__/
 *.pyc