ci(wasm): drop the artifact upload, which cannot work on Gitea

With the build fixed, `trunk build --release` succeeds and the job then
died on its last step:

  ::error:: @actions/artifact v2.0.0+, upload-artifact@v4+ and
            download-artifact@v4+ are not currently supported on GHES.

Gitea presents as GHES and the action aborts by design -- go-gitea/gitea
#31256 and #36024. Same class as the trunk-action bug this branch already
fixes: an action written for GitHub's hosted fleet, on a runner that is not
it.

Dropped rather than downgraded, because nothing consumes the artifact.
`web-dist` had exactly one reference in the repository -- the line that
produced it. There is no `download-artifact`, no deploy step, and no second
workflow. It was failing the job for no benefit.

The two ways to keep it are recorded in the file rather than here, because
choosing between them needs a fact this run does not provide (the runner's
node version) or a supply-chain decision (a third-party action).

What now runs end to end on aarch64, from scratch:

  Install Trunk             ok   (v0.5.1, the arch fix, on the real runner)
  cargo check wasm32        ok
  trunk build --release     ok   10m 56s, 3 files in dist/

Refs #11

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -132,11 +132,17 @@ jobs:
       - name: Build WASM release with Trunk
         run: trunk build --release
 
-      - name: Upload WASM dist artifact
-        uses: actions/upload-artifact@v4
-        with:
-          name: web-dist
-          path: dist/
+      # No artifact upload. actions/upload-artifact@v4 hard-refuses on Gitea --
+      # Gitea presents as GHES and @actions/artifact v2+ aborts there
+      # (go-gitea/gitea#31256, #36024). Nothing consumes `web-dist`: it had
+      # exactly one reference in this repository, the line that produced it,
+      # and there is no download-artifact and no second workflow. The job's
+      # purpose -- proving the web build compiles -- is met by the step above.
+      # Add it back when something consumes the bundle, and decide then between
+      # actions/upload-artifact@v3 (the GHES guidance names v3.2.2 / the
+      # -node20 tag, so check the runner's node first) and the Gitea-specific
+      # christopherHX/gitea-upload-artifact@v4, which is a third-party
+      # dependency and therefore a decision, not a swap.
 
   # ── Format check ─────────────────────────────────────────────────────────────
   fmt: