Upgrade Yarn and make patch script explicit (#474)

The workspace's Yarn is patched lightly, making the patches more explicit by including the file used for this.

Author: miorel

.yarn/releases/patch-yarn.mjs

@@ -0,0 +1,53 @@
+#!/usr/bin/env node
+
+// Example usage:
+//   ./patch-yarn.mjs < yarn-4.5.1.cjs > yarn-4.5.1-patched.cjs
+//   chmod +x yarn-4.5.1-patched.cjs
+
+import process from "node:process";
+
+process.stdin.setEncoding("utf8");
+
+const chunks = [];
+
+process.stdin.on("data", (chunk) => {
+  chunks.push(chunk);
+});
+
+process.stdin.on("end", () => {
+  const source = chunks.join("");
+
+  const versionMatch = source.match(
+    /name:\s*"@yarnpkg\/cli",\s*version:\s*"([^"]+)"/,
+  );
+  if (!versionMatch) {
+    console.error("Couldn't parse the Yarn version from the source.");
+    process.exit(1);
+  }
+
+  const version = versionMatch[1];
+  if (version.endsWith("-patched")) {
+    console.error(
+      `Found Yarn version ${version}, which is already marked as patched.`,
+    );
+    process.exit(1);
+  }
+
+  console.log(
+    source
+      // Prevents the deletion of the "private" field from `package.json`
+      // files.
+      .replaceAll(/\bdelete [^\.]+\.private\b/g, "true")
+
+      // Patches the `yarn workspaces foreach` command to identify itself via
+      // the environment.
+      .replaceAll(
+        /\bProcess started[^;]*;/g,
+        (match) =>
+          `${match}process.env.CODE_CHRONICLES_RUNNING_VIA_YARN_WORKSPACES_FOREACH="1";`,
+      )
+
+      // Updates the Yarn version to indicate that we patched it.
+      .replaceAll(`"${version}"`, `"${version}-patched"`),
+  );
+});