Electron Releases

npx resolves versions from the registry at invocation time, bypassing yarn.lock integrity checks. Replace all build-time uses with pinned equivalents:

• nan-spec-runner — reorder yarn install before node-gyp rebuild, invoke third_party/nan/node_modules/node-gyp/bin/node-gyp.js directly. We control nan's yarn.lock via patch, so the version is already pinned. Drops the 'latest' fallback and Windows shell: true.
• publish-to-npm — use host npm view with try/catch on E404 (modern npm exits 1 on 404; the old empty-string check was npm@6 behavior). Closes the existing TODO.
• upload-symbols — add @sentry/cli@1.62.0 to devDependencies (with dependenciesMeta.built: true so the native binary installs), invoke from node_modules/.bin/sentry-cli.
• script/lib/npx.py — dead since #48243 (yarn v4 migration replaced the DEPS hook).

Notes: none