chore: read commit SHA from event file

Author: mrlubos

dist/index.js

@@ -47,7 +47,21 @@ export async function upload({
   formData.append('ci_platform', 'github')
 
   if (process.env.GITHUB_SHA) {
-    formData.append('commit_sha', process.env.GITHUB_SHA)
+    let commitSha = process.env.GITHUB_SHA
+
+    if (
+      process.env.GITHUB_EVENT_NAME === 'pull_request' &&
+      process.env.GITHUB_EVENT_PATH
+    ) {
+      const event = JSON.parse(
+        fs.readFileSync(process.env.GITHUB_EVENT_PATH, 'utf-8')
+      )
+      if (event?.pull_request?.head?.sha) {
+        commitSha = event.pull_request.head.sha
+      }
+    }
+
+    formData.append('commit_sha', commitSha)
   }
 
   if (dryRun) {