check if PIP_CONSTRAINT works now

readthedocs/readthedocs.org#7258 (comment)

Author: adehad

.readthedocs.yml

@@ -7,13 +7,9 @@ build:
   os: ubuntu-22.04
   tools:
     python: "3.8"
-  jobs:
-    # Work-around to actually constrain dependencies
-    # https://github.com/readthedocs/readthedocs.org/issues/7258#issuecomment-1094978683
-    post_install:
-      - python -m pip install --upgrade --upgrade-strategy eager --no-cache-dir .[docs] -c constraints.txt
 
 python:
+  # PIP_CONSTRAINT=constraints.txt set in the RTD web interface
   install:
     - method: pip
       path: .