chore: re-enable cache for lowest-direct tests

Cache was never the issue - the problem was test subprocesses using
wrong resolution strategy, which is now fixed via UV_RESOLUTION env var.

Author: felixweinberger

.github/workflows/shared.yml

@@ -50,7 +50,7 @@ jobs:
       - name: Install uv
         uses: astral-sh/setup-uv@v3
         with:
-          enable-cache: ${{ matrix.dep-resolution.name != 'lowest-direct' }}
+          enable-cache: true
           version: 0.9.5
 
       - name: Install the project