Set hd and hdrp-blank templates to use Input System exclusively in 6000.1 [ISX-2217]

[Pauliusd01]

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Checklist for PR maker

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Purpose of this PR

There's a drive for better Input System adoption in 6000.1 and one way we're doing this is by updating key templates. All this PR does is change the input backend to Input System exclusive and adds a dependency for it.

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Testing status

Ran every available scene looking for unexpected issues. The third person controller in the hd template already uses Input System so that worked fine out of the box

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Comments to reviewers

Do note that this is going into the master branch. I don't know how to target the 6.1 Editor only 😅 I believe the graphics team will handle landing though

[lyndon-unity]

Good to see input system version updated and set to Input System only

I see there are input action assets already present in the projects
Was slightly surprised the input system package dependency was missing for hdrp-blank given that there was the input action asset in the project.

Note this is related to task https://jira.unity3d.com/browse/ISX-2217
Which is related to this Epic https://jira.unity3d.com/browse/ISX-2214

[lyndon-unity]

On reflection I think its the manifest.json file that also needs changing. Not just the package.json file

[lyndon-unity]

Thanks for the more comprehensive update with changelogs and version updates