use java 17 features

[pjfanning]

Dead JDK detection removed (Smile)

• SmileParser.java — Removed JDK11_OR_LATER reflection check and two dead else branches in _decodeShortAsciiName and _decodeShortAsciiValue (-53 lines)

Collections/Arrays → List.of()/Set.of()/Map.of()

• AvroAnnotationIntrospector.java — Collections.singletonList → List.of
• AvroSchemaHelper.java — new HashSet<>(Arrays.asList(...)) → Set.of(...), Arrays.asList → List.of
• EnumLookup.java — Collections.emptySet → Set.of, Collections.singletonList → List.of, Arrays.asList → List.of
• TypeResolver.java — Collections.emptyMap → Map.of
• ProtobufSchemaPreprocessor.java — new HashSet<>(Arrays.asList(...)) → Set.of(...)

Charset.forName("UTF-8") → StandardCharsets.UTF_8

• ProtobufGenerator.java
• ProtobufSchemaLoader.java
• Proto3LabellessField708Test.java

instanceof pattern matching (Java 16)

• avro (3 sites) — AvroAnnotationIntrospector, CustomEncodingSerializer, RecordVisitor
• cbor (3 sites) — CBORParser (2), CBORSimpleValue
• ion (11 sites) — IonGenerator (2), IonParser, IonValueDeserializer (3), TimestampSerializer, EnumAsIonSymbolSerializer, IonAnnotationTypeDeserializer (2), IonAnnotationTypeSerializer
• protobuf (9 sites) — TypeResolver (6), NativeProtobufSchema (2), ProtobufField, FieldTypes

[github-actions]

🧪 Code Coverage Report

Coverage Type	Coverage	Change
📝 Instructions		📈 +0.07%
🔀 Branches		📈 +0.02%