Revert "FIX install test dependencies"

This reverts commit d2608f3.

Author: tomMoral

.github/workflows/test_benchmarks.yml

@@ -89,14 +89,13 @@ jobs:
         then
           user=${BENCHOPT_BRANCH%@*}
           branch=${BENCHOPT_BRANCH##*@}
-          version="@git+https://github.com/$user/benchopt@$branch"
+          pip install -U git+https://github.com/$user/benchopt@$branch
         elif [[ "$BENCHOPT_VERSION" == "latest" ]]
         then
-          version=""
+          pip install -U benchopt
         else
-          version=$BENCHOPT_VERSION
+          pip install -U benchopt==$BENCHOPT_VERSION
         fi
-        pip install -U benchopt[test]$version
     - name: Check if benchopt is compatible with this benchmark
       id: check_min_version
       run: |