Deprecate `Passthru` parameter on `Get-WebFile` PowerShell helper

[AdmiringWorm]

Is Your Feature Request Related To A Problem? Please describe.

In version 0.9.10 the parameter Passthru was changed to a recommendation of not using it, and had been left due to backwards compatibility.
As this is recommended to not be used, we should deprecate its use and output a warning if it is used with a pending removal in the next major version.

Describe The Solution. Why is it needed?

It makes sense to deprecate anything that we do recommend to not be used, instead of purely leaving it as a comment.

Additional Context.

Link to DO NOT USE comment:

choco/src/chocolatey.resources/helpers/functions/Get-WebFile.ps1

Lines 60 to 61 in 19d7dd1

	.PARAMETER PassThru
	DO NOT USE - holdover from original function.

Related Issues

TODO: Add a link to an issue that will eventually remove this deprecation.

[gep13]

We decided that this wasn't going out with 1.0.0, right? Should we assign to 1.1.0 so that it doesn't get lost?

[AdmiringWorm]

Yeah, we decided not to deprecate it in v1, I've changed the milestone to 1.1.0.