dev-python/sqlalchemy-migrate: fix CI check

moved from ::gentoo
new package, add 0.13.0

Signed-off-by: Huang Rui <vowstar@gmail.com>

dev-python/sqlalchemy-migrate/files/sqlalchemy-migrate-0.13-disable-sphinx-exts.patch

@@ -0,0 +1,13 @@
+intersphinx: prevent resource downloads at build time\
+--- a/doc/source/conf.py
++++ b/doc/source/conf.py
+@@ -28,8 +28,7 @@ sys.path.append(os.path.dirname(os.path.abspath('.')))
+ 
+ # Add any Sphinx extension module names here, as strings. They can be extensions
+ # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
+-extensions = ['sphinx.ext.autodoc',
+-              'sphinx.ext.intersphinx']
++extensions = ['sphinx.ext.autodoc']
+ 
+ # link to sqlalchemy docs
+ intersphinx_mapping = {