Simplify inference of the SupportedDbKind

We used to try to derive it from the dbKind string, falling back to
attempting to interpret the Hibernate ORM "DB Product Name".

But the "DB Product Name" can only be set in situation where *we have a
dbKind string already*, so the fallback is pointless.

Since the fallback also has problems (use of CommunityDatabase which is
not necessarily in the classpath), we might as well remove it.

Author: yrodiere

extensions/hibernate-orm/deployment/src/main/java/io/quarkus/hibernate/orm/deployment/util/HibernateProcessorUtil.java

@@ -26,8 +26,6 @@
 import jakarta.persistence.ValidationMode;
 
 import org.hibernate.cfg.AvailableSettings;
-import org.hibernate.community.dialect.CommunityDatabase;
-import org.hibernate.dialect.Database;
 import org.hibernate.id.SequenceMismatchStrategy;
 import org.hibernate.jpa.boot.spi.JpaSettings;
 import org.hibernate.jpa.boot.spi.PersistenceUnitDescriptor;
@@ -114,6 +112,9 @@ public static Optional<SupportedDatabaseKind> setDialectAndStorageEngine(
             for (DatabaseKindDialectBuildItem item : dbKindDialectBuildItems) {
                 if (dbKind.isPresent() && DatabaseKind.is(dbKind.get(), item.getDbKind())
                         || explicitDialect.isPresent() && item.getMatchingDialects().contains(explicitDialect.get())) {
+                    if (dbKind.isEmpty()) {
+                        dbKind = Optional.ofNullable(item.getDbKind());
+                    }
                     dbProductName = item.getDatabaseProductName();
                     if (dbProductName.isEmpty() && explicitDialect.isEmpty()) {
                         dialect = item.getDialectOptional();
@@ -145,9 +146,6 @@ public static Optional<SupportedDatabaseKind> setDialectAndStorageEngine(
         }
 
         Optional<SupportedDatabaseKind> supportedDbKind = dbKind.flatMap(SupportedDatabaseKind::from);
-        if (supportedDbKind.isEmpty()) {
-            supportedDbKind = supportedDatabaseKindFromProductName(dbProductName);
-        }
 
         handleDialectSpecificSettings(
                 persistenceUnitName,
@@ -216,42 +214,6 @@ private static void handleDialectSpecificSettings(
         }
     }
 
-    private static Optional<SupportedDatabaseKind> supportedDatabaseKindFromProductName(
-            Optional<String> dbProductNameOptional) {
-
-        return dbProductNameOptional
-                .filter(s -> !s.isEmpty())
-                .flatMap(dbProductName -> {
-
-                    if (Database.DB2.productNameMatches(dbProductName)) {
-                        return Optional.of(SupportedDatabaseKind.DB2);
-                    }
-                    if (CommunityDatabase.DERBY.productNameMatches(dbProductName)) {
-                        return Optional.of(SupportedDatabaseKind.DERBY);
-                    }
-                    if (Database.H2.productNameMatches(dbProductName)) {
-                        return Optional.of(SupportedDatabaseKind.H2);
-                    }
-                    if (Database.MARIADB.productNameMatches(dbProductName)) {
-                        return Optional.of(SupportedDatabaseKind.MARIADB);
-                    }
-                    if (Database.MYSQL.productNameMatches(dbProductName)) {
-                        return Optional.of(SupportedDatabaseKind.MYSQL);
-                    }
-                    if (Database.ORACLE.productNameMatches(dbProductName)) {
-                        return Optional.of(SupportedDatabaseKind.ORACLE);
-                    }
-                    if (Database.POSTGRESQL.productNameMatches(dbProductName)) {
-                        return Optional.of(SupportedDatabaseKind.POSTGRESQL);
-                    }
-                    if (Database.SQLSERVER.productNameMatches(dbProductName)) {
-                        return Optional.of(SupportedDatabaseKind.MSSQL);
-                    }
-                    return Optional.empty();
-
-                });
-    }
-
     private static void handleStorageEngine(
             Optional<SupportedDatabaseKind> supportedDatabaseKind,
             String persistenceUnitName,