Update branding to 8.0.311

[vseanreesermsft]

No description provided.

[nagilson]

`It_targets_the_right_framework_depending_on_output_type` is failing with C:\h\w\AF850952\t\dotnetSdkTests\mlginlsx.zsy\Framework_tar---22FC904E\FrameworkTargetTest\FrameworkTargetTest.csproj : error NU1301: Unable to load the service index for source https://dotnetfeed.blob.core.windows.net/dotnet-core/index.json.
C:\h\w\AF850952\t\dotnetSdkTests\mlginlsx.zsy\Framework_tar---22FC904E\FrameworkT`
argetTest\FrameworkTargetTest.csproj : error NU1301:   Response status code does not indicate success: 403 (This request is not authorized to perform this operation.).

store_nativeonlyassets is failing with /datadisks/disk1/work/B30C09BA/w/B02C09A6/e/testExecutionDirectory/store_nativeo---A35DBDA8/UnmanagedStore.csproj : error NU1301: Unable to load the service index for source

https://dotnetfeed.blob.core.windows.net/dotnet-core/index.json seems to not be accessible which is causing tests to fail here. I wonder if this is an outage.

[nagilson]

https://builds.dotnet.microsoft.com/dotnet/release-metadata/releases-index.json this is the new CDN and it looks like the old one went offline which is causing some tests that rely on the old url to fail.

[nagilson]

I was wrong, the old one is a nuget feed. This test doesn't exist in main anymore after @edvilme looked at it... hm

[nagilson]

https://github.com/dotnet/sdk/pull/45420/files#diff-f812af7c156c137bb650227f65c8d715777782230e3236b3111ea905bbb5c372

[marcpopMSFT]

Per edvilme, all of the failures are in tests that were deleted in 9 so we're going to merge on red and backport the removal.