Microsoft.DataFactory/factories/pipelines: "httpRequestTimeout is not allowed of type "WebActivityTypeProperties"

### Resource Type

Microsoft.DataFactory/factories/pipelines

### Api Version

2018-06-01

### Issue Type

Type is unavailable

### Other Notes

Hi,

while deploying the Bicep file for Azure data factory pipelines. I got the below error

it shows that -
httpRequestTimeout in typeProperties - "WebActivityType" is not allowed however it should be allowed as per the official bicep documentation.

Below is the documentation link
https://learn.microsoft.com/en-us/azure/templates/microsoft.datafactory/factories/pipelines?pivots=deployment-language-bicep#webactivity

Thanks

### Bicep Repro

_No response_

### Confirm

- [X] I have read the troubleshooting guide and looked for duplicates.

Start by comparing the Microsoft.DataFactory/factories/pipelines API version 2018-06-01 type definition with the official Bicep WebActivity documentation, focusing on WebActivityTypeProperties and httpRequestTimeout. Confirm the reported deployment error and determine whether the type definition or documentation is inconsistent; done means the allowed property matches the documented behavior.

Written by the indexing model from the issue text.