ci: fix github action yml syntax error for test-long

I missed the error because this workflow gets triggered only when the PR is merged.

The result run from my github action is available in https://github.com/hyangah/vscode-go/actions/runs/138926703.

(Windows test is really slow and we have test failures to investigate.)

Change-Id: If04ff980ca43b4b22515c99187fc06d56542a4ee
GitHub-Last-Rev: 758d40dc048e01e0b617bc7e3a3e3120738a89c1
GitHub-Pull-Request: golang/vscode-go#238
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/238617
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
diff --git a/.github/workflows/test-long.yml b/.github/workflows/test-long.yml
index c3fbf12..9cc67d4 100644
--- a/.github/workflows/test-long.yml
+++ b/.github/workflows/test-long.yml
@@ -1,9 +1,10 @@
 name: Long Tests
 
-on: [push]
-  branches-ignore:
-    - 'latest'
-    - 'upstream'
+on:
+  push:
+    branches-ignore:
+      - 'latest'
+      - 'upstream'
 
 jobs:
   build:
@@ -79,4 +80,4 @@
       
       - name: Lint check
         run: npm run lint
-        if: ${{ matrix.os }} == 'ubuntu-latest'
\ No newline at end of file
+        if: ${{ matrix.os }} == 'ubuntu-latest'