Remove enableRoslynAnalyzers from codespace default settings

Follow up to https://github.com/dotnet/roslyn/pull/60165

We don't think this is the right default as users probably don't want this unless they have at least 8 cores.

.devcontainer/devcontainer.json

@@ -36,7 +36,6 @@
     "omnisharp.disableMSBuildDiagnosticWarning": true,
     "omnisharp.enableEditorConfigSupport": true,
     "omnisharp.enableImportCompletion": true,
-    "omnisharp.enableRoslynAnalyzers": true,
     "omnisharp.useModernNet": true,
     "omnisharp.enableAsyncCompletion": true,
     // ms-vscode.powershell settings
@@ -54,4 +53,4 @@
     "ms-azure-devops.azure-pipelines"
   ],
   "postCreateCommand": "${containerWorkspaceFolder}/restore.sh"
-}
+}