[FIX] core: fix migration order

When we list the versions to upgrade we go over the values in
`self.migrations[pkg.name]`. This object is a mapping of mappings
`{script_location: {version: scripts_list}}`. The location could be
`module` or `module_upgrades` for local scripts, or `upgrade` for
scripts in any of the extra upgrade paths.

The problem is that if we have a minor version that matches a major one
in different locations the order is non-deterministic. For example if we
have a local upgrade script in `1.2`, and an extra upgrade script in
`16.0.1.2`. Both `version` keys (`1.2` and `16.0.1.2`) will resolve to
`16.0.1.2` when ordering. But the order they _actually_ appear in the
set of versions is non-deterministic --due to the `set` implementation
in Python.

The solution is to use a container that keeps the order, in this case a
`dict`.

closes odoo#234209

X-original-commit: 55f6062
Signed-off-by: Christophe Simonis (chs) <chs@odoo.com>
Signed-off-by: Alvaro Fuentes Suarez (afu) <afu@odoo.com>

Author: aj-fuentes

odoo/modules/migration.py

@@ -167,7 +167,7 @@ def convert_version(version):
 
         def _get_migration_versions(pkg, stage):
             versions = sorted({
-                ver
+                ver: None
                 for lv in self.migrations[pkg.name].values()
                 for ver, lf in lv.items()
                 if lf