vscode: do not enable smart case search

in workspace settings. This comes down to user preference
and there's no particular reason to change this based on the workspace.
I found it confusing to have this non-default behavior
just for PX4 editing.

.vscode/settings.json

@@ -128,7 +128,6 @@
                 "${workspaceFolder}/build": true
         },
         "search.showLineNumbers": true,
-        "search.smartCase": true,
         "telemetry.enableTelemetry": false,
         "terminal.integrated.copyOnSelection": true,
         "terminal.integrated.rightClickBehavior": "paste",