chore: update Speakeasy OpenAPI generator to v2.950.11 and bump CLI to v0.4.4

Sync `third_party/golang/github_com/speakeasy_api/openapi_generation/v/v2` to `https://github.com/speakeasy-api/openapi-generation@d5e7284` (`v2.950.11`), bump the CLI version to `0.4.4`, and regenerate all SDKs (Python, TypeScript, Java, Go, Dotnet, and CLI).

- Make temporary directory cleanup non-fatal in the CLI Windows install script (`scripts/install.ps1`) by using `[System.IO.Directory]::Delete($path, $true)` inside a `try/catch` block so 8.3 short-path `$env:TEMP` resolution issues on Windows PowerShell do not fail a completed installation (`dd4b186`).
- Use literal shells for the Windows installer CI matrix (`77ec7f4`).
- Set up latest PHP 8.3 in `test-generator` and keep Composer timeout (`6caffd4`).
- Bump CLI version from `0.4.3` to `0.4.4`.

PiperOrigin-RevId: 1005013488

Author: google-genai-bot

.github/workflows/unit-tests.yml

@@ -9,7 +9,7 @@ on:
       - main
 
 env:
-  SPEAKEASY_VERSION: v2.950.8
+  SPEAKEASY_VERSION: v2.950.11
 
 jobs:
   unit-test: