chore(build): migrate from yarn v1 to pnpm

.gitignore

@@ -26,6 +26,7 @@ build/Release
 # Dependency directory
 # https://www.npmjs.org/doc/misc/npm-faq.html#should-i-check-my-node_modules-folder-into-git
 node_modules
+.pnpm-store/
 integration-tests/gatsby-cli/execution-folder/*
 *.un~
 dist

.gitpod.yml

@@ -2,16 +2,18 @@ image:
   file: .gitpod.Dockerfile
 tasks:
   - init: >
-      yarn run bootstrap &&
+      pnpm run bootstrap &&
       cd ./examples/using-typescript &&
-      yarn install &&
+      # Pin Yarn 1 explicitly so this nested example does not inherit the repo
+      # root pnpm packageManager metadata.
+      env COREPACK_ENABLE_STRICT=0 corepack yarn@1.22.22 install &&
       gatsby-dev --set-path-to-repo ../.. &&
       gatsby-dev --scan-once &&
       npx gatsby build &&
       cd ../.. &&
       touch /tmp/done.txt
     command: >
-      yarn run watch --scope={gatsby,gatsby-link}
+      pnpm run watch --scope={gatsby,gatsby-link}
   - openMode: split-right
     before: >
       cd ./examples/using-typescript
@@ -31,5 +33,3 @@ tasks:
 ports:
   - port: 8000
     onOpen: open-preview
-  - port: 31997 # yarn mutex
-    onOpen: ignore

.npmrc

@@ -0,0 +1,4 @@
+node-linker=isolated
+shamefully-hoist=true
+link-workspace-packages=true
+prefer-workspace-packages=true

.prettierignore

@@ -1,5 +1,6 @@
 *.min.js
 **/node_modules/**
+pnpm-lock.yaml
 flow-typed
 deprecated-packages