Address changes between metadata_cassandra and metadata_scylla

[dkropachev]

We have not updated metadata_cassandra for a while and now it is not operational:

SCYLLA_IMAGE=scylladb/scylla:6.2.0 ./integration.sh scylla  
==> Stopping Scylla
WARN[0000] /extra/scylladb/gocql/docker-compose.yml: `version` is obsolete 
[+] Running 5/5
 ✔ Container gocql-node_1-1  Removed                                                                                                                                                                                            0.0s 
 ✔ Container gocql-node_4-1  Removed                                                                                                                                                                                            0.0s 
 ✔ Container gocql-node_3-1  Removed                                                                                                                                                                                            0.0s 
 ✔ Container gocql-node_2-1  Removed                                                                                                                                                                                            0.0s 
 ✔ Network gocql_public      Removed                                                                                                                                                                                            0.2s 
==> Running Scylla scylladb/scylla:6.2.0
6.2.0: Pulling from scylladb/scylla
Digest: sha256:5b53a7c60d9f9555bb87791ff29b2e633c6f472aec00de7afaf4db1addc6d594
Status: Downloaded newer image for scylladb/scylla:6.2.0
docker.io/scylladb/scylla:6.2.0
WARN[0000] /extra/scylladb/gocql/docker-compose.yml: `version` is obsolete 
[+] Running 5/5
 ✔ Network gocql_public      Created                                                                                                                                                                                            0.1s 
 ✔ Container gocql-node_2-1  Healthy                                                                                                                                                                                           12.2s 
 ✔ Container gocql-node_1-1  Healthy                                                                                                                                                                                           12.2s 
 ✔ Container gocql-node_3-1  Healthy                                                                                                                                                                                           12.1s 
 ✔ Container gocql-node_4-1  Healthy                                                                                                                                                                                           22.6s 
==> Running cassandra tests with args: -gocql.timeout=60s -proto=4 -rf=1 -clusterSize=1 -autowait=2000ms -compressor=snappy -gocql.cversion=3.11.4 -cluster=192.168.100.11
# github.com/gocql/gocql [github.com/gocql/gocql.test]
./cassandra_test.go:2101:6: TestGetKeyspaceMetadata redeclared in this block
        ./cassandra_only_test.go:179:6: other declaration of TestGetKeyspaceMetadata
./cassandra_test.go:2135:6: TestGetKeyspaceMetadataFails redeclared in this block
        ./cassandra_only_test.go:213:6: other declaration of TestGetKeyspaceMetadataFails
./conn.go:1525:30: c.session.schemaDescriber.addTablet undefined (type *schemaDescriber has no field or method addTablet)
./events.go:131:21: s.schemaDescriber.removeTabletsWithKeyspace undefined (type *schemaDescriber has no field or method removeTabletsWithKeyspace)
./events.go:138:21: s.schemaDescriber.removeTabletsWithTable undefined (type *schemaDescriber has no field or method removeTabletsWithTable)
./host_source.go:880:29: r.session.schemaDescriber.removeTabletsWithHost undefined (type *schemaDescriber has no field or method removeTabletsWithHost)
./policies.go:666:38: session.schemaDescriber.getTablets undefined (type *schemaDescriber has no field or method getTablets)
./scylla_cdc.go:92:19: tableMeta.Options undefined (type *TableMetadata has no field or method Options)
./session.go:280:23: s.schemaDescriber.setTablets undefined (type *schemaDescriber has no field or method setTablets)
./session.go:618:27: s.schemaDescriber.getTablets undefined (type *schemaDescriber has no field or method getTablets)
./session.go:618:27: too many errors
FAIL    github.com/gocql/gocql [build failed]

Let's fix it and add it to the - run: ./integration.sh cassandra scylla
:

      - run: ./integration.sh cassandra

FYI: schemaDescriber was renamed to metadataDesciber at #356