Update BSP connection build server config lookup path

Resolves #1695

Adopt `<workspace_root>/.bsp` search locations in addition to
`<workspace_root>/`.

Author: Rajveer100

Sources/BuildSystemIntegration/ExternalBuildSystemAdapter.swift

@@ -94,10 +94,18 @@ actor ExternalBuildSystemAdapter {
   private var lastRestart: Date?
 
   static package func projectRoot(for workspaceFolder: AbsolutePath, options: SourceKitLSPOptions) -> AbsolutePath? {
-    guard localFileSystem.isFile(workspaceFolder.appending(component: "buildServer.json")) else {
-      return nil
+    let buildServerConfigLocations = [
+      workspaceFolder.appending(component: "buildServer.json"),
+      workspaceFolder.appending(components: [".bsp", "buildServer.json"])
+    ]
+
+    for buildServerConfigLocation in buildServerConfigLocations {
+      if localFileSystem.isFile(buildServerConfigLocation) {
+        return workspaceFolder
+      }
     }
-    return workspaceFolder
+
+    return nil
   }
 
   init(