Revert "ci: install upstream ddtrace wheel during PR-triggered unit t… #712

Job	Run time
build	1m 6s
system-tests / Get parameters / Get parameters	13s
system-tests / Build end-to-end (apigw-http)	1m 22s
system-tests / Build end-to-end (function-url)	1m 13s
system-tests / Build end-to-end (alb)	1m 29s
system-tests / Build end-to-end (alb-multi)	1m 23s
system-tests / Build end-to-end (apigw-rest)	1m 11s
system-tests / parametric	0s
system-tests / End-to-end #1 / alb-multi 1	3m 43s
system-tests / End-to-end #1 / alb 1	3m 59s
system-tests / End-to-end #1 / apigw-rest 1	3m 24s
system-tests / End-to-end #1 / apigw-http 1	3m 18s
system-tests / End-to-end #1 / function-url 1	3m 54s
system-tests / Report failures	0s
	26m 15s

Provide feedback