po: make dist depend on update-po

This works around a race condition with gettext Makefile.

https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/merge_requests/1094#note_1435313

.gitlab-ci/run-test.sh

@@ -20,6 +20,9 @@ fi
 
 do_clean() {
     git clean -fdx
+    # "make -C update-po", run on "make dist" has a silly habit of
+    # modifying files in-tree. Lets undo that.
+    git checkout -- po/
 }
 
 uname -a

po/Makevars

@@ -75,4 +75,4 @@ PO_DEPENDS_ON_POT = no
 # regenerate PO files on "make dist".  Possible values are "yes" and
 # "no".  Set this to no if the POT file and PO files are maintained
 # externally.
-DIST_DEPENDS_ON_UPDATE_PO = no
+DIST_DEPENDS_ON_UPDATE_PO = yes