[7.17] Fix check-docs failing due to use of StartUpInfo instead of ConnInfo

[cmacknz]

Fixes the failure in https://github.com/elastic/beats/actions/runs/9488427065/job/26147333159?pr=39832

mage check
>> fmt - go-licenser: Adding missing headers
>> fmt - goimports: Formatting Go code
>> Building elastic-agent.yml for linux/amd64
>> Building elastic-agent.reference.yml for linux/amd64
>> Building elastic-agent.docker.yml for linux/amd64
>> Buildspec from spec/*.yml to pkg/agent/program/supported.go
>> BuildPGP from GPG-KEY-elasticsearch to pkg/release/pgp.go
>> BuildFleetCfg _meta/elastic-agent.fleet.yml to pkg/agent/application/configuration_embed.go
go: downloading github.com/otiai10/copy v1.2.0
go: downloading github.com/kardianos/service v1.2.1-0.20210728001519-a323c3813bc7
go: downloading github.com/hectane/go-acl v0.0.0-20190604041725-da78bae5fc95
go: downloading github.com/gorilla/mux v1.7.3
go: downloading github.com/antlr/antlr4 v0.0.0-20200820155224-be881fa6b91d
go: downloading github.com/oklog/ulid v1.3.1
>> check: Checking source code for common problems
# github.com/elastic/beats/v7/x-pack/elastic-agent/pkg/agent/operation/tests/scripts/serviceable-1.0-darwin-x86_64
Error: vet: pkg/agent/operation/tests/scripts/serviceable-1.0-darwin-x86_64/main.go:105:33: undefined: proto.StartUpInfo
Error: failed running go vet, please fix the issues reported: running "go vet ./..." failed with exit code 1
make[1]: *** [../../dev-tools/make/mage.mk:21: check] Error 1
make[1]: Leaving directory '/home/runner/work/beats/beats/x-pack/elastic-agent'
make: *** [Makefile:97: check] Error 1

[elasticmachine]

Pinging @elastic/elastic-agent-control-plane (Team:Elastic-Agent-Control-Plane)