Upgrade sbuilder from v2.4.3 to the released v2.5.0, bringing sqd v1.2.0 transitively. Align the minimum Go version and CI builders to 1.23; CI uses locked dependency downloads and readonly tests instead of changing module versions. Validated with GOWORK=off on Go 1.23.4: full -race suite (36 tested packages), live PostgreSQL 17 CRUD using the repository fixtures, go vet and go mod verify. Independent review found no blockers. Recommended release after merge: v2.6.0. This library and edispatcher-pg can be released independently; downstream application MRs are deferred until both tags exist, so each application receives final dependency versions once. Task: https://fsd-group.atlassian.net/browse/IN-785