Add ability to use ddtrace_serverless wheels in layer build #556

Job	Run time
build	1m 4s
system-tests / Get parameters / Get parameters	10s
system-tests / Build end-to-end (alb-multi)	1m 11s
system-tests / Build end-to-end (function-url)	1m 13s
system-tests / Build end-to-end (apigw-rest)	1m 10s
system-tests / Build end-to-end (apigw-http)	1m 17s
system-tests / Build end-to-end (alb)	1m 13s
system-tests / parametric	0s
system-tests / End-to-end #1 / alb-multi 1	3m 2s
system-tests / End-to-end #1 / apigw-rest 1	3m 50s
system-tests / End-to-end #1 / alb 1	3m 51s
system-tests / End-to-end #1 / function-url 1	2m 51s
system-tests / End-to-end #1 / apigw-http 1	3m 51s
system-tests / Report failures	0s
	24m 43s

Provide feedback