pythonPackages.virtualenvwrapper: Fix post install (closes #21168)

pkgs/top-level/python-packages.nix

@@ -26105,11 +26105,12 @@ in {
         local wrapped="$out/bin/.$file-wrapped"
         mv "$wrapper" "$wrapped"
 
-        cat > "$wrapper" <<- EOF
-        export PATH="$PATH:\$PATH"
-        export VIRTUALENVWRAPPER_PYTHONPATH="$PYTHONPATH:$(toPythonPath $out)"
-        source "$wrapped"
-        EOF
+        # WARNING: Don't indent the lines below because that would break EOF
+        cat > "$wrapper" << EOF
+export PATH="$PATH:\$PATH"
+export VIRTUALENVWRAPPER_PYTHONPATH="$PYTHONPATH:$(toPythonPath $out)"
+source "$wrapped"
+EOF
 
         chmod -x "$wrapped"
         chmod +x "$wrapper"