[Internal] Remove deprecated online tables integration test (#5101)

## Changes
<!-- Summary of your changes that are easy to understand -->
Creation of online tables is not supported as they are deprecated:
https://docs.databricks.com/aws/en/machine-learning/feature-store/online-tables
```
  | Error: cannot create online table: Online Table is being deprecated. Creating new online table is not allowed. Databricks recommends switching to Synced Tables.
  | 
  |   with databricks_online_table.this,
  |   on terraform_plugin_test.tf line 52, in resource "databricks_online_table" "this":
  |   52:   resource "databricks_online_table" "this" {
```

Due to this CI tests are failing leading to PRs not being merged 

## Tests
<!--
How is this tested? Please see the checklist below and also describe any
other relevant tests
-->
All existing integration tests passes now. CI is green

NO_CHANGELOG=true

Author: tanmay-db