Publish tarballs with .tgz extension

[eps1lon]

Not sure if this is appropriate here.

yarn v2 no longer installs packages from arbitrary urls.

Right now

diff --git a/package.json b/package.json
index 2f92273..b2e2b2a 100644
--- a/package.json
+++ b/package.json
@@ -3,6 +3,7 @@
   "version": "0.1.0",
   "private": true,
   "dependencies": {
+    "@material-ui/core": "https://pkg.csb.dev/mui-org/material-ui/commit/e9a9cdb2/@material-ui/core",
     "@testing-library/jest-dom": "^5.11.4",
     "@testing-library/react": "^11.1.0",
     "@testing-library/user-event": "^12.1.10",

fails with

$ yarn
➤ YN0000: ┌ Resolution step
➤ YN0001: │ Error: @material-ui/core@https://pkg.csb.dev/mui-org/material-ui/commit/e9a9cdb2/@material-ui/core isn't supported by any available resolver
    at i.getResolverByDescriptor (/home/eps1lon/Development/throwaway/cra4-mui5-react17/.yarn/releases/yarn-2.3.3.cjs:2:314629)

I asked in their discord and they confirmed that tarballs need the .tgz extension. I tried if this url already existed but got a 404: https://pkg.csb.dev/mui-org/material-ui/commit/e9a9cdb2/@material-ui/core.tgz

Alternatives:

1. download as .tgz and install does not work since the codesandbox replaced dependency ranges with https://csb.*
2. write custom yarn resolver