fix pyproject formatting

Author: timkpaine

.bumpversion.cfg

@@ -8,6 +8,6 @@ search = __version__ = "{current_version}"
 replace = __version__ = "{new_version}"
 
 [bumpversion:file:pyproject.toml]
-search = version="{current_version}"
-replace = version="{new_version}"
+search = version = "{current_version}"
+replace = version = "{new_version}"