Run the CI suite on the Windows runner again

This reverts b268891. The first push with the suite on stein2 turned
both jobs red, because gate and suite shared the four cores of one
machine.

- Gate 761 had one red test: tilemap-patch.test.ts took 7.45 s against
  the 5 s limit. The gate needed 12 min instead of about 2.5 min.
- Suite 762 had 8 red timing, audio and render checks out of 2156 and
  took 25 min instead of about 12.5 min on melektaus-atx.
- The suite runs on `feuerwerk-wsl` again, the gate stays on
  `feuerwerk-ci`. The header of ci.yml is back to its old text.

Tests: YAML unchanged against the state before b268891. Not run in CI
yet, the next push starts it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.gitea/workflows/ci.yml

@@ -1,19 +1,19 @@
 # Runs the whole proof on the Gitea runner: gate, the editor suite and the three example games.
 #
-# Both jobs run on `feuerwerk-ci`, the runner on stein2. Its label picks the image built from
-# tools/ci/Dockerfile. The GPU (/dev/dri/renderD128) and /dev/shm come from that runner's own
-# config.yaml, not from here – without them chromium falls back to software WebGL and the harness
-# stops. The suite ran on `feuerwerk-wsl` in the WSL2 distro feuerwerk-ci on melektaus-atx (#283),
-# whose config adds /dev/dxg and FEUERWERK_BROWSER=wsl. Pointing the suite at that label again
-# moves the browser runs back there. It moved to stein2 because other jobs on melektaus-atx share
-# its GPU and made the suite's frame timings wobble.
+# The suite runs on `feuerwerk-wsl`, the runner in the WSL2 distro feuerwerk-ci on
+# melektaus-atx (#283). Its label picks the image built from tools/ci/Dockerfile. The GPU
+# (/dev/dxg and the Windows driver libraries), /dev/shm and FEUERWERK_BROWSER=wsl come from that
+# runner's own config.yaml, not from here – without them chromium falls back to software WebGL and
+# the harness stops. The gate needs no GPU and runs on `feuerwerk-ci`, the runner on stein2 with
+# the same image. Pointing the suite at that label too moves the browser runs back to stein2.
 #
 # Two jobs without `needs:`, so they start together. The gate does not stand in front of the
 # suite: a lint error used to cost the full e2e run before it was reported, and the run reported
 # it after six minutes instead of one. Both still have to pass for the push to be green.
 #
-# On one runner the gate's vitest shares cores with the suite's chromium, which measures text
-# widths and frame counts. GM_TEST_WORKERS caps vitest at two workers for that.
+# On two runners the gate's vitest no longer shares cores with the suite's chromium, which
+# measures text widths and frame counts. GM_TEST_WORKERS still caps vitest at two workers, for the
+# day both jobs share one runner again.
 name: feuerwerk
 
 on:
@@ -51,7 +51,7 @@ jobs:
           php tests/php/rights.test.php
 
   suite:
-    runs-on: feuerwerk-ci
+    runs-on: feuerwerk-wsl
     timeout-minutes: 45
     steps:
       - uses: actions/checkout@v4