Chore: removes props mutation (#2056)

While investigating some potential mutations
[here](https://ops.grafana-ops.net/d/83f4951f-2ef3-4260-91a0-39a031992b75/getmutationobserverproxy-logs)
I was able to find these mutating
[lines](https://github.com/grafana/grafana-zabbix/blob/main/src/datasource/components/ConfigEditor.tsx#L55-L57)

Although this works right now, this might not work in future Grafana
versions. This PR makes sure we don't mutate the props.

I haven't been able to test this manually so I could use some help to
make sure the plugin works as expected.

---------

Co-authored-by: ivanahuckova <ivana.huckova@gmail.com>

.changeset/metal-bottles-sin.md

@@ -0,0 +1,5 @@
+---
+'grafana-zabbix': patch
+---
+
+Fix: Remove props mutation in config editor