Bump cloud.google.com/go/iam from 1.2.0 to 1.2.1 (#1745) #3564

Job	Run time
build	48s
staticcheck	1m 18s
lint	13s
tests (macos/go-1.22-amd64)	1m 8s
tests (ubuntu/go-1.22-386)	56s
tests (ubuntu/go-1.22-amd64)	1m 0s
tests (windows/go-1.22-386)	3m 26s
tests (windows/go-1.22-amd64)	3m 29s
tests (macos/go-1.23-amd64)	1m 23s
tests (ubuntu/go-1.23-386)	54s
tests (ubuntu/go-1.23-amd64)	1m 7s
tests (windows/go-1.23-386)	2m 2s
tests (windows/go-1.23-amd64)	2m 29s
test-python-example	31s
test-gsutil-example	33s
test-node-example	9s
test-go-example	31s
test-dotnet-example	14s
test-scala-example	38s
test-java-example	20s
test-cpp-example	2m 18s
test-curl-example	9s
test-curl-both-scheme-default-ports-example	14s
test-curl-both-scheme-non-default-ports-example	6s
unblock-pr	1s
	25m 57s

Provide feedback