UX: Better error handling if `replaces:` block needed, and hide help on error

[Dentrax]

Idea is to rephrase the following error to clarify a bit and show to further steps:

• gobump should check if the package in the replaces block in the go.mod file, if so append a message something like: "Please put your package bump in the 'replaces:' block".
• Hide show-help-on-error. It feels like there is a CLI usage error but actually there isn't. We should only show up the help if the CLI usage is wrong.

2025/04/03 12:08:46 WARN Error: failed to run update. Error: package github.com/docker/docker with version 'v23.0.15+incompatible' is already at version v25.0.6+incompatible
2025/04/03 12:08:46 WARN Usage:
2025/04/03 12:08:46 WARN   gobump [flags]
2025/04/03 12:08:46 WARN   gobump [command]
2025/04/03 12:08:46 WARN
2025/04/03 12:08:46 WARN Available Commands:
2025/04/03 12:08:46 WARN   completion  Generate the autocompletion script for the specified shell
2025/04/03 12:08:46 WARN   help        Help about any command
2025/04/03 12:08:46 WARN   version     Prints the version
2025/04/03 12:08:46 WARN
2025/04/03 12:08:46 WARN Flags:
2025/04/03 12:08:46 WARN       --bump-file string    Filename containing the list of packages to update / replace
2025/04/03 12:08:46 WARN       --compat string       set the go version for which the tidied go.mod and go.sum files should be compatible
2025/04/03 12:08:46 WARN       --go-version string   set the go-version for go-mod-tidy
2025/04/03 12:08:46 WARN   -h, --help                help for gobump
2025/04/03 12:08:46 WARN       --modroot string      path to the go.mod root
2025/04/03 12:08:46 WARN       --packages string     A space-separated list of packages to update
2025/04/03 12:08:46 WARN       --replaces string     A space-separated list of packages to replace
2025/04/03 12:08:46 WARN       --show-diff           Show the difference between the original and 'go.mod' files
2025/04/03 12:08:46 WARN       --skip-initial-tidy   Skip running 'go mod tidy' command before updating the go.mod file
2025/04/03 12:08:46 WARN       --tidy                Run 'go mod tidy' command
2025/04/03 12:08:46 WARN
2025/04/03 12:08:46 WARN Use "gobump [command] --help" for more information about a command.
2025/04/03 12:08:46 WARN
2025/04/03 12:08:46 WARN 2025/04/03 12:08:46 failed to run update. Error: package github.com/docker/docker with version 'v23.0.15+incompatible' is already at version v25.0.6+incompatible