Introduce EJBCA UpstreamAuthority plugin for SPIRE Server #8470

Job	Run time
cache-deps (windows)	1m 12s
cache-deps (linux)	40s
images (linux)	6m 12s
Build matrix	3s
lint (linux)	5m 1s
unit-test (ubuntu-22.04)	4m 50s
unit-test (linux with race detection)	6m 21s
unit-test (macos-latest)	4m 36s
artifacts (windows)	5m 51s
lint (windows)	8m 45s
unit-test (windows)	8m 55s
integration-k8s	0s
artifacts (linux)	0s
integration (linux)	0s
images (windows)	0s
integration (windows)	0s
success	0s
	52m 26s

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