Trying to install wasi-experimental workload doesn't work if dotnet is installed via snap

On Ubuntu if you install dotnet using snap, then you will get this error when you try to install the wasi-experimental workload:

> sudo dotnet workload install wasi-experimental
Unhandled exception: System.IO.IOException: Read-only file system : '/snap/dotnet-sdk/245/metadata'
   at System.IO.FileSystem.CreateDirectory(String fullPath, UnixFileMode unixCreateMode)
   at System.IO.Directory.CreateDirectory(String path)
   at Microsoft.DotNet.Workloads.Workload.Install.WorkloadInstallerFactory.CanWriteToDotnetRoot(String dotnetDir)
   at Microsoft.DotNet.Workloads.Workload.Install.WorkloadInstallerFactory.GetWorkloadInstaller(IReporter reporter, SdkFeatureBand sdkFeatureBand, IWorkloadResolver workloadResolver, VerbosityOptions verbosity, String userProfileDir, Boolean verifySignatures, INuGetPackageDownloader nugetPackageDownloader, String dotnetDir, String tempDirPath, PackageSourceLocation packageSourceLocation, RestoreActionConfig restoreActionConfig, Boolean elevationRequired, Boolean shouldLog)
   at Microsoft.DotNet.Workloads.Workload.Install.WorkloadInstallCommand..ctor(ParseResult parseResult, IReporter reporter, IWorkloadResolverFactory workloadResolverFactory, IInstaller workloadInstaller, INuGetPackageDownloader nugetPackageDownloader, IWorkloadManifestUpdater workloadManifestUpdater, String tempDirPath, IReadOnlyCollection`1 workloadIds)
   at Microsoft.DotNet.Cli.WorkloadInstallCommandParser.<>c.<ConstructCommand>b__6_0(ParseResult parseResult)
   at System.CommandLine.Invocation.InvocationPipeline.Invoke(ParseResult parseResult)
   at Microsoft.DotNet.Cli.Program.ProcessArgs(String[] args, TimeSpan startupTime, ITelemetry telemetryClient)

IMO we should at least improve the error message for users when they hit this because its not immediately clear its because of snap.