Set dulwich minimal version to prevent upstream bug (#263)

Guts · web-flow · commit ef7737af408d · 2023-05-07T15:33:44.000+02:00
diff --git a/requirements/base.txt b/requirements/base.txt
@@ -1,5 +1,5 @@
 distro==1.8.* ; sys_platform == 'linux'
-dulwich>=0.20,<0.21.6
+dulwich>=0.21.5,<0.21.6
 giturlparse>=0.10,<0.11
 imagesize>=1.4,<1.5
 packaging>=20,<24
