chore: remove the TypeScript code from the repository (#2048)

This deletes the bulk of the `codex-cli` folder and eliminates the logic
that builds the TypeScript code and bundles it into the release.

Since this PR modifies `.github/workflows/rust-release.yml`, to test
changes to the release process, I locally commented out all of the "is
this commit on upstream `main`" checks in
`scripts/create_github_release.sh` and ran:

```
./codex-rs/scripts/create_github_release.sh 0.20.0-alpha.4
```

Which kicked off:

https://github.com/openai/codex/actions/runs/16842085113

And the release artifacts appear legit!

https://github.com/openai/codex/releases/tag/rust-v0.20.0-alpha.4

codex-cli/tsconfig.json

@@ -1,34 +0,0 @@
-{
-  "compilerOptions": {
-    "outDir": "dist",
-    "module": "ESNext",
-    "moduleResolution": "bundler",
-    "target": "esnext",
-    "lib": [
-      "DOM",
-      "DOM.Iterable",
-      "ES2022" // Node.js 18
-    ],
-    "types": ["node"],
-    "baseUrl": "./",
-    "resolveJsonModule": true, // ESM doesn't yet support JSON modules.
-    "jsx": "react",
-    "declaration": true,
-    "newLine": "lf",
-    "stripInternal": true,
-    "strict": true,
-    "noImplicitReturns": true,
-    "noImplicitOverride": true,
-    "noUnusedLocals": true,
-    "noUnusedParameters": true,
-    "noFallthroughCasesInSwitch": true,
-    "noUncheckedIndexedAccess": true,
-    "noPropertyAccessFromIndexSignature": true,
-    "noUncheckedSideEffectImports": true,
-    "noEmitOnError": true,
-    "useDefineForClassFields": true,
-    "forceConsistentCasingInFileNames": true,
-    "skipLibCheck": true
-  },
-  "include": ["src", "tests", "bin"]
-}