Upgrade to Kotlin 1.7.20

This commit also temporarily changes a test assertion for the Jackson
Kotlin module.
As of https://youtrack.jetbrains.com/issue/KT-52932, Kotlin enhanced the
`IntRange` and this change is not supported yet by the Jackson Kotlin
module. An issue has been reported here:
FasterXML/jackson-module-kotlin#582

Closes gh-29225

spring-web/src/test/java/org/springframework/http/converter/json/Jackson2ObjectMapperBuilderTests.java

@@ -289,7 +289,8 @@ class Jackson2ObjectMapperBuilderTests {
 
 		// Kotlin module
 		IntRange range = new IntRange(1, 3);
-		assertThat(new String(objectMapper.writeValueAsBytes(range), "UTF-8")).isEqualTo("{\"start\":1,\"end\":3}");
+		// temporarily change the assertion, see https://github.com/FasterXML/jackson-module-kotlin/issues/582
+		assertThat(new String(objectMapper.writeValueAsBytes(range), "UTF-8")).isEqualTo("{\"start\":1,\"end\":3,\"endExclusive\":4}");
 	}
 
 	@Test  // gh-22576