ci: skip the Playwright browser download in release builds

The x64 build failed in bootstrap (getaddrinfo ENOTFOUND cdn.playwright.dev)
while playwright-core's postinstall tried to download a Chromium. arm64 and the
test job passed the SAME commit (v0.9.1 → 2e1b857), so this is a transient
network dependency, not a code defect — and an unnecessary one: no LevelCode
build runs Playwright browser tests. playwright-core is pulled in transitively by
the upstream `copilot` extension.

Set PLAYWRIGHT_SKIP_BROWSER_DOWNLOAD=1 on the Build job env, alongside the
GITHUB_TOKEN mitigation that already exists for the same class of problem
(postinstall network fetches). Verified against the installed playwright-core:
installBrowsersForNpmInstall() short-circuits on getAsBooleanFromENV of this exact
var, so the Chromium fetch never runs. Scoped to the Build jobs, not global, so it
can't affect the test job if that ever wants a browser.

Note: v0.9.1 is a TAG, so this does not retroactively fix that release build (a
re-run of the flaked job does); it prevents recurrence for every future release
cut from develop.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: ndemianc

.github/workflows/release.yml

@@ -73,6 +73,11 @@ jobs:
     # release days; GITHUB_TOKEN raises that to 5000/hr. Read-only default token — no extra perms needed.
     env:
       GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      # No LevelCode build runs Playwright browser tests, but an upstream extension (copilot) pulls in
+      # playwright-core, whose postinstall downloads a Chromium from cdn.playwright.dev. That network hop
+      # flaked the x64 build (getaddrinfo ENOTFOUND) while arm64 passed the SAME commit — so skip it and
+      # the whole class of flake goes away. Same spirit as the GITHUB_TOKEN mitigation above.
+      PLAYWRIGHT_SKIP_BROWSER_DOWNLOAD: "1"
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v4