Avoid writing to stdout in LSP #8244

Job	Run time
JS Lint	54s
Compiler output check (ubuntu-latest)	4m 8s
Rust Tests (ubuntu-latest)	4m 23s
Compiler output check (macos-latest)	3m 39s
Build Rust Compiler (ubuntu-latest)	4m 31s
Rust Tests (macos-latest)	3m 26s
Build Rust Compiler (ubuntu-latest)	5m 32s
Build Rust Compiler (macos-latest)	3m 39s
Rust Tests (windows-latest)	6m 24s
Build Rust Compiler (macos-latest)	2m 53s
JS Tests (Node 18.x)	1m 29s
Build Rust Compiler (windows-latest)	8m 34s
JS Tests (Node 20.x)	1m 28s
Rust Lint	18s
Flow Typecheck	38s
VSCode Extension Lint	21s
Publish to NPM	1m 44s
	54m 1s

Provide feedback