Remove BuildXL feed

[JanKrivanek]

Context

BuildXL feed is going to be moved . To shield devs from future feed changes - we have had the BuildXL packages pushed to dotnet-tools feed.

Testing

No testing - successful build on clean build machine without cache is enough

FYI @dfederm

[mthalman]

This needs to be backported for .NET 8 and 9. VMR builds for both of those versions are affected by the removal of this feed. See dotnet/source-build#4634.

[JanKrivanek]

/backport to vs17.12

[github-actions]

Started backporting to vs17.12: https://github.com/dotnet/msbuild/actions/runs/11353473872

[JanKrivanek]

/backport to vs17.8

[github-actions]

Started backporting to vs17.8: https://github.com/dotnet/msbuild/actions/runs/11353479929

[github-actions]

@JanKrivanek backporting to vs17.12 failed, the patch most likely resulted in conflicts:

$ git am --3way --empty=keep --ignore-whitespace --keep-non-patch changes.patch

Applying: Remove BuildXL feed
Using index info to reconstruct a base tree...
M	NuGet.config
Falling back to patching base and 3-way merge...
Auto-merging NuGet.config
CONFLICT (content): Merge conflict in NuGet.config
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
hint: When you have resolved this problem, run "git am --continue".
hint: If you prefer to skip this patch, run "git am --skip" instead.
hint: To restore the original branch and stop patching, run "git am --abort".
hint: Disable this message with "git config advice.mergeConflict false"
Patch failed at 0001 Remove BuildXL feed
Error: The process '/usr/bin/git' failed with exit code 128

Please backport manually!

[github-actions]

@JanKrivanek an error occurred while backporting to vs17.12, please check the run log for details!

Error: git am failed, most likely due to a merge conflict.

[github-actions]

@JanKrivanek backporting to vs17.8 failed, the patch most likely resulted in conflicts:

$ git am --3way --empty=keep --ignore-whitespace --keep-non-patch changes.patch

Applying: Remove BuildXL feed
Using index info to reconstruct a base tree...
M	NuGet.config
Falling back to patching base and 3-way merge...
Auto-merging NuGet.config
CONFLICT (content): Merge conflict in NuGet.config
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
hint: When you have resolved this problem, run "git am --continue".
hint: If you prefer to skip this patch, run "git am --skip" instead.
hint: To restore the original branch and stop patching, run "git am --abort".
hint: Disable this message with "git config advice.mergeConflict false"
Patch failed at 0001 Remove BuildXL feed
Error: The process '/usr/bin/git' failed with exit code 128

Please backport manually!

[github-actions]

@JanKrivanek an error occurred while backporting to vs17.8, please check the run log for details!

Error: git am failed, most likely due to a merge conflict.