fix(ci): use tsdown --workspace with dir path, not --filter

pnpm on next passes `--workspace ./tools/egg-bin` through to tsdown
(pnpm doesn't recognize `--workspace` as its own flag). tsdown's
`--workspace [dir]` expects a directory path, not a package name.

Previous attempts:
  --workspace @eggjs/bin  → "No workspace packages found" (pkg name)
  --filter @eggjs/bin     → works but slower than expected

Correct form matching next: `-- --workspace ./tools/egg-bin`

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: elrrrrrrr

.github/workflows/ci.yml

@@ -208,7 +208,7 @@ jobs:
 
       - name: Run tests
         run: |
-          ut run build -- --filter @eggjs/bin
+          ut run build -- --workspace ./tools/egg-bin
           ut run ci --workspace @eggjs/bin
 
       - name: Code Coverage
@@ -249,7 +249,7 @@ jobs:
 
       - name: Run tests
         run: |
-          ut run build -- --filter @eggjs/scripts
+          ut run build -- --workspace ./tools/scripts
           ut run ci --workspace tools/scripts
 
       - name: Code Coverage