[2022.1] Disabling tests 024, 025 and 026 in Foundation

[ellioman]

Purpose of this PR

Disabling tests

• UniversalGraphicsTests.026_Shader_PBRscene
• UniversalGraphicsTests.024_Shader_PBRvalidation_Specular
• UniversalGraphicsTests.025_Shader_PBRvalidation_Metallic

on iPhone as they are failing.
I've created a bug for the issue.
https://fogbugz.unity3d.com/f/cases/1367380/

The test comes back green with this change
https://yamato.cds.internal.unity3d.com/jobs/902-Graphics/tree/universal%252Fdisable-tests/.yamato%252Furp_foundation-iphone-metal.yml%2523URP_Foundation_iPhone_Metal_Standalone_il2cpp_Linear_trunk/8884419/job

[github-actions]

Hi! This comment will help you figure out which jobs to run before merging your PR. The suggestions are dynamic based on what files you have changed.
Link to Yamato: https://yamato.cds.internal.unity3d.com/jobs/902-Graphics
Search for your PR branch using the sidebar on the left, then add the following segment(s) to the end of the URL (you may need multiple tabs depending on how many packages you change)

URP
/.yamato%252Fall-urp.yml%2523PR_URP_trunk
With changes to URP packages, you should also run
/.yamato%252Fall-lightmapper.yml%2523PR_LightMapper_trunk

Depending on the scope of your PR, you may need to run more jobs than what has been suggested. Please speak to your lead or a Graphics SDET (#devs-graphics-automation) if you are unsure.

[github-actions]

It appears that you made a non-draft PR!
Please convert your PR to draft (button on the right side of the page).
See the PR template for more information.
Thank you!