Finish installation before prerequisite builds

Deno runs sibling task dependencies concurrently. The prerequisite pnpm
builds previously raced pnpm install, which can rewrite executable shims
while a build starts and fail with tsdown permission errors.

Make each prerequisite build depend on install so all shim updates and
installation lifecycle scripts finish before those builds run.

https://github.com/fedify-dev/fedify/actions/runs/37948628519/job/113881481612

Assisted-by: Codex:gpt-6.1-sol

Author: dahlia

deno.json

@@ -117,16 +117,20 @@
       ]
     },
     "pnpm:build-vocab-runtime": {
-      "command": "pnpm -C packages/vocab-runtime build"
+      "command": "pnpm -C packages/vocab-runtime build",
+      "dependencies": ["install"]
     },
     "pnpm:build-vocab-tools": {
-      "command": "pnpm -C packages/vocab-tools build"
+      "command": "pnpm -C packages/vocab-tools build",
+      "dependencies": ["install"]
     },
     "pnpm:build-fixture": {
-      "command": "pnpm -C packages/fixture build"
+      "command": "pnpm -C packages/fixture build",
+      "dependencies": ["install"]
     },
     "pnpm:build-webfinger": {
-      "command": "pnpm -C packages/webfinger build"
+      "command": "pnpm -C packages/webfinger build",
+      "dependencies": ["install"]
     },
     "pnpm:build-vocab": {
       "command": "pnpm -C packages/vocab build",