feat: allow overriding the compared version

Looking at you RustRover, returning a different version than the one in
the release archive.

precheck/unless/unless.go

@@ -18,6 +18,8 @@ type Unless struct {
 	Pwd      string `yaml:"pwd"`
 	Shell    bool   `yaml:"shell"`
 	Stat     string `yaml:"stat"`
+	// For when the returned version is different from what needs to be replace the version part in URL.
+	VersionOutput string `yaml:"version_output"`
 }
 
 func (u Unless) String() string {
@@ -116,6 +118,10 @@ func shouldSkip(unlessable Unlessable, s settings.Settings) bool {
 		return false
 	}
 
+	if unless.VersionOutput != "" {
+		version = unless.VersionOutput
+	}
+
 	if postProc != version {
 		internal.Log.Debugf("%s: existing version `%s`, required version `%s`", name, postProc, version)
 		return false