Declare the OpenAPI v3.0 nullable dependency on type in the walker (#3018)

Signed-off-by: Juan Cruz Viotti <jv@jviotti.com>

Author: jviotti

src/core/jsonschema/known_walker.cc

@@ -3767,7 +3767,7 @@ constexpr std::array<Variant, 728> VARIANTS{{
      .secondary = std::nullopt,
      .result = {SchemaKeywordType::Assertion,
                 Known::OPENAPI_3_0_BASE,
-                {},
+                KEYWORDS_TYPE,
                 {},
                 INSTANCES_ANY}},
     {.vocabulary = Known::JSON_SCHEMA_2020_12_APPLICATOR,

test/jsonschema/jsonschema_walker_openapi_test.cc

@@ -473,7 +473,8 @@ TEST(openapi_3_0_nullable) {
   EXPECT_EQ(result.type, SchemaKeywordType::Assertion);
   EXPECT_TRUE(result.vocabulary.has_value());
   EXPECT_VOCABULARY_KNOWN(result.vocabulary.value(), OPENAPI_3_0_BASE);
-  EXPECT_TRUE(result.dependencies.empty());
+  EXPECT_TRUE(std::ranges::equal(result.dependencies,
+                                 std::to_array<std::string_view>({"type"})));
   EXPECT_TRUE(result.order_dependencies.empty());
   EXPECT_TRUE(result.instances.none());
 }