workflows/eval: remove separate attrpaths step

This was only separate to work around possible delays from the target
branch's eval workflow. With the switch to the merge queue, this delay
is impossible - the relevant target commit will only appear once Eval
has completed in the merge queue, so Eval will be guaranteed to have
finished.

By running attrpaths and outpaths in the same step, we share ~10 seconds
of eval time, traversing through all of Nixpkgs.

.github/workflows/eval.yml

@@ -115,26 +115,6 @@ jobs:
           # If it uses too much memory, slightly decrease chunkSize.
           # Note: Keep the same further down in sync!
 
-      # Running the attrpath generation step separately from the outpath step afterwards.
-      # The idea is that, *if* Eval on the target branch has not finished, yet, we will
-      # generate the attrpaths in the meantime - and the separate command command afterwards
-      # will check cachix again for whether Eval has finished. If no Eval result from the
-      # target branch can be found the second time, we proceed to run it in here. Attrpaths
-      # generation takes roughly 30 seconds, so for every normal use-case this should be more
-      # than enough of a head start for Eval on the target branch to finish.
-      # This edge-case, that Eval on the target branch is delayed is unlikely to happen anyway:
-      # For a commit to become the target commit of a PR, it must *already* be on the branch.
-      # Normally, CI should always start running on that push event *before* it starts running
-      # on the PR.
-      - name: Evaluate the ${{ matrix.system }} attribute paths at the target commit
-        if: inputs.targetSha
-        env:
-          MATRIX_SYSTEM: ${{ matrix.system }}
-        run: |
-          nix-build nixpkgs/trusted/ci --arg nixpkgs ./nixpkgs/trusted-pinned -A eval.attrpathsSuperset \
-            --argstr evalSystem "$MATRIX_SYSTEM" \
-            --argstr nixPath "nixVersions.latest"
-
       - name: Evaluate the ${{ matrix.system }} output paths at the target commit
         if: inputs.targetSha
         env: