Fixes the version used for set version classic (#4827)

Author: arcanis

.yarn/versions/1a212dd8.yml

@@ -0,0 +1,23 @@
+releases:
+  "@yarnpkg/cli": patch
+  "@yarnpkg/plugin-essentials": patch
+
+declined:
+  - "@yarnpkg/plugin-compat"
+  - "@yarnpkg/plugin-constraints"
+  - "@yarnpkg/plugin-dlx"
+  - "@yarnpkg/plugin-init"
+  - "@yarnpkg/plugin-interactive-tools"
+  - "@yarnpkg/plugin-nm"
+  - "@yarnpkg/plugin-npm-cli"
+  - "@yarnpkg/plugin-pack"
+  - "@yarnpkg/plugin-patch"
+  - "@yarnpkg/plugin-pnp"
+  - "@yarnpkg/plugin-pnpm"
+  - "@yarnpkg/plugin-stage"
+  - "@yarnpkg/plugin-typescript"
+  - "@yarnpkg/plugin-version"
+  - "@yarnpkg/plugin-workspace-tools"
+  - "@yarnpkg/builder"
+  - "@yarnpkg/core"
+  - "@yarnpkg/doctor"

packages/plugin-essentials/sources/commands/set/version.ts

@@ -108,7 +108,7 @@ export default class SetVersionCommand extends BaseCommand {
     else if (this.version === `canary`)
       bundleRef = getRef(`https://repo.yarnpkg.com/{}/packages/yarnpkg-cli/bin/yarn.js`, await resolveTag(configuration, `canary`));
     else if (this.version === `classic`)
-      bundleRef = {url: `https://nightly.yarnpkg.com/latest.js`, version: `classic`};
+      bundleRef = {url: `https://classic.yarnpkg.com/latest.js`, version: `classic`};
     else if (this.version.match(/^https?:/))
       bundleRef = {url: this.version, version: `remote`};
     else if (this.version.match(/^\.{0,2}[\\/]/) || npath.isAbsolute(this.version))