tox.ini: Avoid pip >= 22.1.1

Currently, things are failing due to pip-tools not working with pip
>= 22.1.1. So avoid these versions until jazzband/pip-tools#1624
is merged and found in released version.

Signed-off-by: Arnaud Patard <apatard@hupstream.com>

tox.ini

@@ -25,6 +25,7 @@ commands =
 [testenv:deps]
 description = Update project dependencies
 deps =
+    pip < 22.1.1
     pip-tools
 commands =
     pip-compile -q --no-header --no-annotate --output-file=requirements.txt requirements.in