🔧 pin Deno to v2.8.3 in CI
v2.9.0 fails JSR integrity checks on warm cache for files without a
manifest checksum (denoland/deno#35529). Size Report builds twice on
the same runner, so the base build hits the cache and errors on
`@ts-morph/common@0.27.0`'s dynamic `require("./crypto")`.
Restore `v2.x` once v2.9.1 ships.