FoundationEssentials: limit autosave to user domain

[compnerd]

During the review for the changes to support Windows, we realized that the location that is being used for the autosave information is only available within the user domain mask. The Windows implementation was corrected as part of the implementation, but this corrects the XDG compliant path to reflect this reality.

[compnerd]

@swift-ci please test

[jmschonfeld]

I think we'll need to update the unit test here as well:

Test Case 'FileManagerTests.testSearchPaths_XDGEnvironmentVariables' started at 2024-05-28 12:06:24.064
/build/swift-foundation/Tests/FoundationEssentialsTests/FileManager/FileManagerTests.swift:800: error: FileManagerTests.testSearchPaths_XDGEnvironmentVariables : XCTAssertTrue failed - Results [] did not contain known directory /tmp/FileManagerPlayground_E5CBFB28-886D-4572-9A62-6D6CE0FC22FB/TestPath/Autosave Information for autosavedInformationDirectory/SearchPathDomainMask(rawValue: 2) while setting the XDG_DATA_HOME environment variable
/build/swift-foundation/Tests/FoundationEssentialsTests/FileManager/FileManagerTests.swift:802: error: FileManagerTests.testSearchPaths_XDGEnvironmentVariables : XCTAssertTrue failed - Results [] did not contain known directory /tmp/FileManagerPlayground_E5CBFB28-886D-4572-9A62-6D6CE0FC22FB/TestPath/.local/share/Autosave Information for autosavedInformationDirectory/SearchPathDomainMask(rawValue: 2) while setting the HOME environment variable
Test Case 'FileManagerTests.testSearchPaths_XDGEnvironmentVariables' failed (0.003 seconds)

I think to fix it, we can just remove the two validate calls from FileManagerTests.testSearchPaths_XDGEnvironmentVariables that provide .userDomainMask leaving the two that provide .localDomainMask

[compnerd]

@swift-ci please test

[jmschonfeld]

@swift-ci please test