Add unit tests for `uploadPayload` #5937

Job	Run time
Go: tracing with legacy workflow (ubuntu-latest, stable-v2.17.6)	1m 16s
Go: tracing with legacy workflow (ubuntu-latest, stable-v2.19.4)	1m 38s
Go: tracing with legacy workflow (macos-latest, stable-v2.17.6)	3m 4s
Go: tracing with legacy workflow (macos-latest, stable-v2.18.4)	3m 4s
Go: tracing with legacy workflow (macos-latest, default)	3m 3s
Go: tracing with legacy workflow (macos-latest, stable-v2.20.7)	3m 4s
Go: tracing with legacy workflow (ubuntu-latest, stable-v2.18.4)	1m 35s
Go: tracing with legacy workflow (macos-latest, stable-v2.19.4)	3m 3s
Go: tracing with legacy workflow (macos-latest, nightly-latest)	3m 6s
Go: tracing with legacy workflow (ubuntu-latest, stable-v2.22.4)	1m 36s
Go: tracing with legacy workflow (ubuntu-latest, default)	1m 19s
Go: tracing with legacy workflow (ubuntu-latest, stable-v2.21.4)	1m 23s
Go: tracing with legacy workflow (macos-latest, linked)	3m 2s
Go: tracing with legacy workflow (ubuntu-latest, linked)	1m 14s
Go: tracing with legacy workflow (macos-latest, stable-v2.21.4)	3m 7s
Go: tracing with legacy workflow (ubuntu-latest, stable-v2.20.7)	1m 26s
Go: tracing with legacy workflow (macos-latest, stable-v2.22.4)	3m 3s
Go: tracing with legacy workflow (ubuntu-latest, nightly-latest)	1m 20s
	40m 23s

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