[build] inline dev-build upload in deploy.sh (#8868)

Removes the call to `plugin..dart deploy` in favor of a bash
implementation inline.

Fixes: #8866 .


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  <summary>Contribution guidelines:</summary><br>

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---------

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: pq

tool/kokoro/deploy.sh

@@ -10,6 +10,26 @@ echo "kokoro build start"
 echo "kokoro build finished"
 
 echo "kokoro deploy start"
-./bin/plugin deploy --channel=dev
+
+KOKORO_TOKEN_FILE="${KOKORO_KEYSTORE_DIR}/${FLUTTER_KEYSTORE_ID}_${FLUTTER_KEYSTORE_NAME}"
+if [ ! -f "$KOKORO_TOKEN_FILE" ]; then
+  echo "Error: Keystore token file not found at $KOKORO_TOKEN_FILE"
+  exit 1
+fi
+TOKEN=$(cat "$KOKORO_TOKEN_FILE")
+
+ZIP_FILE="build/distributions/flutter-intellij-kokoro.zip"
+if [ ! -f "$ZIP_FILE" ]; then
+  echo "Error: Zip file not found at $ZIP_FILE"
+  exit 1
+fi
+
+echo "Uploading $ZIP_FILE to JetBrains Marketplace..."
+curl -if --fail \
+  --header "Authorization: Bearer $TOKEN" \
+  -F pluginId=9212 \
+  -F file=@"$ZIP_FILE" \
+  -F channel=dev \
+  https://plugins.jetbrains.com/plugin/uploadPlugin
 
 echo "kokoro deploy finished"