Extension produces error on install using MacOS

When installing your extension v0.15.0 on MacOS I received the following error. It does appear that the extension was installed per the CLI message and I can see it in the VSCode extensions list.

```bash
➜ ~ code --install-extension pkl-vscode-0.15.0.vsix
Installing extensions...
(node:25132) [DEP0005] DeprecationWarning: Buffer() is deprecated due to security and usability issues. Please use the Buffer.alloc(), Buffer.allocUnsafe(), or Buffer.from() methods instead.
(Use `Electron --trace-deprecation ...` to show where the warning was created)
Extension 'pkl-vscode-0.15.0.vsix' was successfully installed.
```

System information:
```bash
➜ ~ system_profiler SPSoftwareDataType SPHardwareDataType
Software:

System Software Overview:

System Version: macOS 14.2.1 (23C71)
Kernel Version: Darwin 23.2.0
Boot Volume: Macintosh HD
Boot Mode: Normal
Secure Virtual Memory: Enabled
System Integrity Protection: Enabled
Time since boot: 2 days, 22 hours, 24 minutes

Hardware:

Hardware Overview:

Model Name: MacBook Air
Model Identifier: Mac14,2
Model Number: Z15S000D1LL/A
Chip: Apple M2
Total Number of Cores: 8 (4 performance and 4 efficiency)
Memory: 16 GB
System Firmware Version: 10151.61.4
OS Loader Version: 10151.61.4
Activation Lock Status: Enabled
```

Reproduce the VS Code extension installation with `code --install-extension pkl-vscode-0.15.0.vsix` on the reported macOS and Apple M2 setup, then inspect the emitted deprecation warning. Determine whether the warning represents an installation failure or only diagnostic output; done means the installation behavior and expected CLI output are clearly established.

Written by the indexing model from the issue text.