Release 5.0.2 with error source fix for some downstream errors (#1980)

This PR fixes error source for 2 errors:
- parsing of invalid json response should be downstream error as we
expect to receive valid json from zabbix
- no host found error should be downstream. We are bumping sdk that
includes that fix
https://github.com/grafana/grafana-plugin-sdk-go/pull/1246.

As you can see - the invalid json parsing is now downstream error
<img width="1498" alt="image"
src="https://github.com/user-attachments/assets/88028dbe-0f73-47aa-8262-5729059ce12f"
/>

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Change Log
 
+## [5.0.2] - 2025-02-27
+
+- Chore: Fix error source for parsing of invalid json response
+- Chore: Update github.com/grafana/grafana-plugin-sdk-go to v0.268.0
+
 ## [5.0.1] - 2025-02-24
 
 - Bug fix: Fixed host groups not showing in problems panel