fix regex for windows

src/updaters/python/python-readme.ts

@@ -13,13 +13,13 @@ export class PythonReadme extends DefaultUpdater {
     if (this.version.preRelease) {
       // it's a pre-release, so add the pre-release flag if it's missing
       return content.replace(
-        /^# install from PyPI\n^pip install (\S+)$/gm,
+        /^# install from PyPI\r?\n^pip install (\S+)$/gm,
         '# install from PyPI\npip install --pre $1'
       );
     } else {
       // it's not a pre-release, so remove the pre-release flag if it's present
       return content.replace(
-        /^# install from PyPI\n^pip install --pre (\S+)$/gm,
+        /^# install from PyPI\r?\n^pip install --pre (\S+)$/gm,
         '# install from PyPI\npip install $1'
       );
     }