Add checks for no matching of migration functions count and the length of `migrations` defined in `migrations.go`
For example, for `v284 -> v285`
![image](/attachments/e43c465e-d41f-4755-950d-d3565690ea2a)
remove line 556:
![image](/attachments/a8598239-f123-415a-8090-3bdb781ce6ab)
run `make lint-go-vet`:
![image](/attachments/7a55b7be-6c19-41b5-995f-98d4aa5a7100)
Reviewed-on: https://gitea.com/gitea/gitea-vet/pulls/27
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: yp05327 <576951401@qq.com>
Co-committed-by: yp05327 <576951401@qq.com>