CI / PR having issues provisioning resources

[jaredpar]

Builds are failing with the following error message:

##[Error 1]
An error occurred while provisioning resources (Error Type: Disconnect). 

##[Warning 1]
Received request to deprovision: The request was cancelled by the remote provider. 

Build	Kind	Timeline Record
591699	PR #32107	Libraries Test Run release mono OSX x64 Debug
591368	Rolling	Installer Build and Test iOS_x64 Release
591316	Rolling	CoreCLR Product Build OSX x64 release
591101	Rolling	Installer Build and Test iOS_arm64 Release
590735	Rolling	CoreCLR Product Build OSX x64 release
590527	PR #34601	Installer Build and Test iOS_arm64 Debug
590287	Rolling	Mono Product Build iOS arm64 release
590193	PR #33608	CoreCLR Product Build OSX x64 checked
590153	PR #34297	CoreCLR Product Build OSX x64 release
590118	PR #34475	Installer Build and Test OSX_x64 Debug
590031	PR #34563	Mono Product Build iOS arm64 debug
589968	PR #32592	CoreCLR Product Build OSX x64 checked

Evaluated 100 builds
Impacted 12 builds
Impacted 12 jobs

[MattGal]

Just got off the IcM bridge with the hosted mac pool folks, and the problem seems to be different than the last time. As noted in https://github.com/dotnet/core-eng/issues/9448, there was a new feature turned on that had a bug and was subsequently turned off; this was not the case here, rather it seems the builds are filling up the disks.

Some more points:

• The MMS team does not have information on the available disk space of a given MacOS build agent, and even if they did this would change up and down randomly as the workloads installed on the machines are modified and rolled out. They suggest adding some disk usage commands to the beginning of builds so this can be monitored.
• They suggest "deleting any files you like" as an initial step in build if the size of the build cannot be reduced (not kidding)

[jaredpar]

This is a dupe of #34472