Build(deps): Bump cloud.google.com/go/functions in /function

Bumps [cloud.google.com/go/functions](https://github.com/googleapis/google-cloud-go) from 1.15.4 to 1.16.0.
- [Release notes](https://github.com/googleapis/google-cloud-go/releases)
- [Changelog](https://github.com/googleapis/google-cloud-go/blob/main/documentai/CHANGES.md)
- [Commits](googleapis/google-cloud-go@kms/v1.15.4...asset/v1.16.0)

---
updated-dependencies:
- dependency-name: cloud.google.com/go/functions
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

function/go.mod

@@ -6,7 +6,7 @@ toolchain go1.21.0
 
 require (
 	cloud.google.com/go/firestore v1.14.0
-	cloud.google.com/go/functions v1.15.4
+	cloud.google.com/go/functions v1.16.0
 	cloud.google.com/go/pubsub v1.36.1
 	github.com/cockroachdb/errors v1.11.1
 	github.com/deckarep/golang-set v1.8.0

function/go.sum

@@ -7,8 +7,8 @@ cloud.google.com/go/compute/metadata v0.2.3 h1:mg4jlk7mCAj6xXp9UJ4fjI9VUI5rubuGB
 cloud.google.com/go/compute/metadata v0.2.3/go.mod h1:VAV5nSsACxMJvgaAuX6Pk2AawlZn8kiOGuCv6gTkwuA=
 cloud.google.com/go/firestore v1.14.0 h1:8aLcKnMPoldYU3YHgu4t2exrKhLQkqaXAGqT0ljrFVw=
 cloud.google.com/go/firestore v1.14.0/go.mod h1:96MVaHLsEhbvkBEdZgfN+AS/GIkco1LRpH9Xp9YZfzQ=
-cloud.google.com/go/functions v1.15.4 h1:ZjdiV3MyumRM6++1Ixu6N0VV9LAGlCX4AhW6Yjr1t+U=
-cloud.google.com/go/functions v1.15.4/go.mod h1:CAsTc3VlRMVvx+XqXxKqVevguqJpnVip4DdonFsX28I=
+cloud.google.com/go/functions v1.16.0 h1:IWVylmK5F6hJ3R5zaRW7jI5PrWhCvtBVU4axQLmXSo4=
+cloud.google.com/go/functions v1.16.0/go.mod h1:nbNpfAG7SG7Duw/o1iZ6ohvL7mc6MapWQVpqtM29n8k=
 cloud.google.com/go/iam v1.1.5 h1:1jTsCu4bcsNsE4iiqNT5SHwrDRCfRmIaaaVFhRveTJI=
 cloud.google.com/go/iam v1.1.5/go.mod h1:rB6P/Ic3mykPbFio+vo7403drjlgvoWfYpJhMXEbzv8=
 cloud.google.com/go/kms v1.15.5 h1:pj1sRfut2eRbD9pFRjNnPNg/CzJPuQAzUujMIM1vVeM=