[for testing only] Ensure all data is written before closing FoundationStreamBridge #3164

Job	Run time
apple (macos-13-xlarge, Xcode_14.1, platform=iOS Simulator,OS=16.1,name=iPhone 14)	6m 41s
linux (jammy, 5.7)	6m 51s
apple (macos-13-xlarge, Xcode_14.1, platform=tvOS Simulator,OS=16.1,name=Apple TV 4K (3rd generat...	4m 50s
linux (jammy, 5.10)	6m 40s
apple (macos-13-xlarge, Xcode_14.1, platform=OS X)	4m 31s
linux (amazonlinux2, 5.7)	6m 55s
apple (macos-14-xlarge, Xcode_15.3, platform=iOS Simulator,OS=17.4,name=iPhone 15)	5m 39s
linux (amazonlinux2, 5.10)	7m 2s
apple (macos-14-xlarge, Xcode_15.3, platform=tvOS Simulator,OS=17.4,name=Apple TV 4K (3rd generat...	5m 19s
apple (macos-14-xlarge, Xcode_15.3, platform=OS X)	5m 24s
	59m 52s

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