[chore] Fix a Swagger warning that only manifests during Go client code generation (#2729)

docs/api/swagger.yaml

@@ -1018,7 +1018,7 @@ definitions:
                     - public
                 items:
                     $ref: '#/definitions/filterContext'
-                minLength: 1
+                minItems: 1
                 type: array
                 uniqueItems: true
                 x-go-name: Context

internal/api/model/filterv1.go

@@ -40,7 +40,7 @@ type FilterV1 struct {
 	Phrase string `json:"phrase"`
 	// The contexts in which the filter should be applied.
 	//
-	// Minimum length: 1
+	// Minimum items: 1
 	// Unique: true
 	// Enum:
 	//	- home