Upgrade from 14.10.4 to LTS 15.10.8 fails in database migration

The database is a Postgresql 13.14 (RockyLinux 9.3).

Caused by: org.hibernate.exception.SQLGrammarException: Error accessing index information: activitystream_events
        at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:103)
        at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:37)
        at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:113)
        at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:99)
        at org.hibernate.tool.schema.extract.internal.AbstractInformationExtractorImpl.convertSQLException(AbstractInformationExtractorImpl.java:124)
        at org.hibernate.tool.schema.extract.internal.AbstractInformationExtractorImpl.getIndexes(AbstractInformationExtractorImpl.java:1171)
        at org.hibernate.tool.schema.extract.internal.TableInformationImpl.indexes(TableInformationImpl.java:122)
        at org.hibernate.tool.schema.extract.internal.TableInformationImpl.getIndex(TableInformationImpl.java:138)
        at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.findMatchingIndex(AbstractSchemaMigrator.java:361)
        at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.applyIndexes(AbstractSchemaMigrator.java:345)
        at org.hibernate.tool.schema.internal.GroupedSchemaMigratorImpl.performTablesMigration(GroupedSchemaMigratorImpl.java:88)
        at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.performMigration(AbstractSchemaMigrator.java:220)
        at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.doMigration(AbstractSchemaMigrator.java:123)
        at org.hibernate.tool.hbm2ddl.SchemaUpdate.execute(SchemaUpdate.java:94)
        at org.hibernate.tool.hbm2ddl.SchemaUpdate.execute(SchemaUpdate.java:63)
        at com.xpn.xwiki.internal.store.hibernate.HibernateStore.updateDatabase(HibernateStore.java:1171)
        at com.xpn.xwiki.internal.store.hibernate.HibernateStore.updateDatabase(HibernateStore.java:1038)
        at com.xpn.xwiki.internal.store.hibernate.HibernateStore.updateDatabase(HibernateStore.java:1205)
        at com.xpn.xwiki.store.XWikiHibernateBaseStore.updateSchema(XWikiHibernateBaseStore.java:264)
        at com.xpn.xwiki.store.migration.hibernate.HibernateDataMigrationManager.hibernateShemaUpdate(HibernateDataMigrationManager.java:214)
        at com.xpn.xwiki.store.migration.hibernate.HibernateDataMigrationManager.updateSchema(HibernateDataMigrationManager.java:195)
        ... 21 common frames omitted
Caused by: org.postgresql.util.PSQLException: ERROR: column i.indproc does not exist
  Hint: Perhaps you meant to reference the column "i.indpred".
  Position: 610
        at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2157)
        at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1886)
        at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:255)
        at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:559)
        at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:403)
        at org.postgresql.jdbc2.AbstractJdbc2Statement.executeQuery(AbstractJdbc2Statement.java:283)
        at org.postgresql.jdbc2.AbstractJdbc2DatabaseMetaData.getIndexInfo(AbstractJdbc2DatabaseMetaData.java:4202)
        at org.apache.commons.dbcp2.DelegatingDatabaseMetaData.getIndexInfo(DelegatingDatabaseMetaData.java:418)
        at org.apache.commons.dbcp2.DelegatingDatabaseMetaData.getIndexInfo(DelegatingDatabaseMetaData.java:418)
        at org.hibernate.tool.schema.extract.internal.InformationExtractorJdbcDatabaseMetaDataImpl.processIndexInfoResultSet(InformationExtractorJdbcDatabaseMetaDataImpl.java:112)
        at org.hibernate.tool.schema.extract.internal.AbstractInformationExtractorImpl.getIndexes(AbstractInformationExtractorImpl.java:1131)
        ... 36 common frames omitted