fix: rule severity should be different than the default one

pkg/config/severity.go

@@ -20,6 +20,11 @@ func (s *Severity) Validate() error {
 	}
 
 	for i, rule := range s.Rules {
+		if s.Default == rule.Severity {
+			return fmt.Errorf("error in severity rule #%d: the default severity (%q) is the same as the rule severity, this rule can be removed",
+				i, s.Default)
+		}
+
 		if err := rule.Validate(); err != nil {
 			return fmt.Errorf("error in severity rule #%d: %w", i, err)
 		}

pkg/config/severity_test.go

@@ -79,6 +79,21 @@ func TestSeverity_Validate_error(t *testing.T) {
 			},
 			expected: "error in severity rule #0: severity should be set",
 		},
+		{
+			desc: "same severity between default and rule",
+			severity: &Severity{
+				Default: "high",
+				Rules: []SeverityRule{
+					{
+						Severity: "high",
+						BaseRule: BaseRule{
+							Path: "test",
+						},
+					},
+				},
+			},
+			expected: `error in severity rule #0: the default severity ("high") is the same as the rule severity, this rule can be removed`,
+		},
 	}
 
 	for _, test := range testCases {