ci: drop global typescript install

Nothing invokes a bare tsc; build and ts-jest both use the local
typescript devDependency. The global 5.8.3 predated the TS 6 pin and
could only shadow it.

.gitea/workflows/build.yaml

@@ -26,7 +26,6 @@ jobs:
           mise install pnpm
           mise reshim
           echo "$HOME/.local/share/mise/shims" >> "$GITHUB_PATH"
-          npm install -g typescript@5.8.3
 
       - name: Install just
         run: |