TrueZip64 tests take a significant amount of time to run locally and run by default

[vcsjones]

I occasionally run libs.test subset (or Copilot decides to do it for me) and some of these ZIP64 tests take a significant amount of time to run on a MacBook Neo.

ystem.IO.Compression.ZipFile.Tests: [Long Running Test] 'System.IO.Compression.Tests.ZipFile_EncryptionTests.Encryption_TrueZip64_LargeEntry_RoundTrip', Elapsed: 00:04:08
     System.IO.Compression.ZipFile.Tests: [Long Running Test] 'System.IO.Compression.Tests.ZipFile_EncryptionTests.Encryption_TrueZip64_LargeEntry_RoundTrip', Elapsed: 00:06:08
     System.IO.Compression.ZipFile.Tests: [Long Running Test] 'System.IO.Compression.Tests.ZipFile_EncryptionTests.Encryption_TrueZip64_LargeEntry_RoundTrip', Elapsed: 00:08:08
     System.IO.Compression.ZipFile.Tests: [Long Running Test] 'System.IO.Compression.Tests.ZipFile_EncryptionTests.Encryption_TrueZip64_LargeEntry_RoundTrip', Elapsed: 00:10:08
     System.IO.Compression.ZipFile.Tests: [Long Running Test] 'System.IO.Compression.Tests.ZipFile_EncryptionTests.Encryption_TrueZip64_LargeEntry_UpdateMode_Throws', Elapsed: 00:02:04
     System.IO.Compression.ZipFile.Tests: [Long Running Test] 'System.IO.Compression.Tests.ZipFile_EncryptionTests.Encryption_TrueZip64_LargeEntry_UpdateMode_Throws', Elapsed: 00:04:04

These tests are already marked SkipCI - perhaps we should consider marking them outer loop. I do not think contributors that want to work in System.IO.Compression want a test suite that takes 15 minutes to complete.

[dotnet-policy-service]

Tagging subscribers to this area: @karelz, @dotnet/area-system-io-compression
See info in area-owners.md if you want to be subscribed.