Try all possible python paths when launching language server

[jmanuel1]

No description provided.

[Copilot]

Pull request overview

This PR modifies the language server startup logic to try multiple Python executable paths instead of just using the first one. If a Python path fails with an ENOENT error, the client now recursively tries the next path in the list until a working Python executable is found or all paths are exhausted.

Key Changes:

• Implemented recursive fallback logic for trying multiple Python paths when starting the language server
• Extracted isErrnoException helper function to a shared error utility module
• Added comprehensive test coverage for both success and failure scenarios

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
language-concat/lib/lsp-client.ts	Added startServerProcessUsingFoundPython method with recursive fallback logic and process error handling
language-concat/lib/error.ts	Created new shared utility module for the isErrnoException type guard function
language-concat/lib/concat.ts	Removed local isErrnoException function in favor of imported shared version
language-concat/spec/lsp-client-spec.js	Added test cases for successful server startup with multiple paths and error handling when Python is not found

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[coveralls]

coverage: 80.639%. remained the same
when pulling 3da2041 on fix-lsp-startup
into 9071963 on master.