Set pnpm version in ci

[NullVoxPopuli]

Alternate to #21416

[github-actions]

📊 Size report

Tarball size — 1.2 MB → 1.2 MB

dist/dev   No changes

File	Before (Size / Brotli)	After (Size / Brotli)
./packages/shared-chunks/template-{hash}.js	491 B / 203 B	118%↑1.1 kB / 98%↑401 B
Total (Includes all files)	2 MB / 478.1 kB	2 MB / 478.1 kB

---

dist/prod   No changes

File	Before (Size / Brotli)	After (Size / Brotli)
Total (Includes all files)	1.8 MB / 436 kB	1.8 MB / 436 kB

---

smoke-tests/v2-app-hello-world-template/dist   No changes

File	Before (Size / Brotli)	After (Size / Brotli)
Total (Includes all files)	235 kB / 64.4 kB	235 kB / 64.4 kB

_{🤖 This report was automatically generated by wyvox/pkg-size}