vscode: Copy the compile_commands.json from build to source dir

No longer needed to symlink it to make clangd work

code.dev.code-workspace

@@ -32,7 +32,8 @@
     "todo-tree.filtering.excludeGlobs": [
       "**/ECM",
       "**/3rdparty"
-    ]
+    ],
+    "cmake.copyCompileCommands": "${workspaceFolder}/compile_commands.json"
   },
   "launch": {
     "version": "0.2.0",
@@ -136,4 +137,4 @@
       }
     ]
   }
-}
+}