misc: change the "taskName" to "label" in vscode tasks.json (#10739)

because of vscode suggest
ref ISSUE: Microsoft/vscode-docs#1181

Signed-off-by: a101211279 <1012112796@qq.com>

contrib/ide/vscode/tasks.json

   "version": "2.0.0",
   "tasks": [
     {
-      "taskName": "Build",
+      "label": "Build",
       "type": "shell",
       "command": "go",
       "group": "build",
       "problemMatcher": ["$go"]
     },
     {
-      "taskName": "Build (with SQLite3)",
+      "label": "Build (with SQLite3)",
       "type": "shell",
       "command": "go",
       "group": "build",