chore(deps): update module github.com/cloudevents/sdk-go/v2 to v2.15.2 [security]

Author: renovate-bot

go.mod

@@ -4,6 +4,6 @@ go 1.11
 
 require (
 	cloud.google.com/go/functions v1.16.1
-	github.com/cloudevents/sdk-go/v2 v2.14.0
+	github.com/cloudevents/sdk-go/v2 v2.15.2
 	github.com/google/go-cmp v0.6.0
 )

go.sum

@@ -1356,6 +1356,8 @@ github.com/chzyer/test v0.0.0-20210722231415-061457976a23/go.mod h1:Q3SI9o4m/ZMn
 github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
 github.com/cloudevents/sdk-go/v2 v2.14.0 h1:Nrob4FwVgi5L4tV9lhjzZcjYqFVyJzsA56CwPaPfv6s=
 github.com/cloudevents/sdk-go/v2 v2.14.0/go.mod h1:xDmKfzNjM8gBvjaF8ijFjM1VYOVUEeUfapHMUX1T5To=
+github.com/cloudevents/sdk-go/v2 v2.15.2 h1:54+I5xQEnI73RBhWHxbI1XJcqOFOVJN85vb41+8mHUc=
+github.com/cloudevents/sdk-go/v2 v2.15.2/go.mod h1:lL7kSWAE/V8VI4Wh0jbL2v/jvqsm6tjmaQBSvxcv4uE=
 github.com/cncf/udpa/go v0.0.0-20191209042840-269d4d468f6f/go.mod h1:M8M6+tZqaGXZJjfX53e64911xZQV5JYwmTeXPW+k8Sc=
 github.com/cncf/udpa/go v0.0.0-20200629203442-efcf912fb354/go.mod h1:WmhPx2Nbnhtbo57+VJT5O0JRkEi1Wbu0z5j0R8u5Hbk=
 github.com/cncf/udpa/go v0.0.0-20201120205902-5459f2c99403/go.mod h1:WmhPx2Nbnhtbo57+VJT5O0JRkEi1Wbu0z5j0R8u5Hbk=