Set consistency prior to calling CreateSesion

[dave92082]

Fixes #24648 by setting the consistency level of the cluster prior to creating the session.

Tested using AWS Keyspaces after this fix:

• Vault Status:

Key                Value
---                -----
Seal Type          shamir
Initialized        true
Sealed             true
Total Shares       3
Threshold          3
Unseal Progress    0/3
Unseal Nonce       n/a
Version            1.16.0-beta1
Build Date         2023-12-29T11:33:31Z
Storage Type       cassandra
HA Enabled         false

• Startup Log:

==> Vault server configuration:

Administrative Namespace: 
             Api Address: http://127.0.0.1:8200
                     Cgo: disabled
         Cluster Address: https://127.0.0.1:8201
   Environment Variables: AWS_PROFILE, COMMAND_MODE, GO111MODULE, GOFLAGS, HOME, HOMEBREW_CELLAR, HOMEBREW_PREFIX, HOMEBREW_REPOSITORY, INFOPATH, LC_CTYPE, LOGNAME, MANPATH, NVM_BIN, NVM_CD_FLAGS, NVM_DIR, NVM_INC, OLDPWD, PATH, PNPM_HOME, PWD, SHELL, SHLVL, SSH_AUTH_SOCK, TERM, TERMINAL_EMULATOR, TERM_SESSION_ID, TMPDIR, USER, XPC_FLAGS, XPC_SERVICE_NAME, 
              Go Version: go1.21.5
              Listener 1: tcp (addr: "127.0.0.1:8200", cluster address: "127.0.0.1:8201", max_request_duration: "1m30s", max_request_size: "33554432", tls: "disabled")
               Log Level: 
                   Mlock: supported: false, enabled: false
           Recovery Mode: false
                 Storage: cassandra
                 Version: Vault v1.16.0-beta1, built 2023-12-29T11:33:31Z
             Version Sha: 4dace235ced0a69cf447c58a56083aca5861fb74

==> Vault server started! Log data will stream in below:

2023-12-29T11:59:35.786-0800 [INFO]  proxy environment: http_proxy="" https_proxy="" no_proxy=""
2023-12-29T11:59:37.570-0800 [INFO]  incrementing seal generation: generation=1
2023-12-29T11:59:38.073-0800 [INFO]  core: Initializing version history cache for core
2023-12-29T11:59:38.073-0800 [INFO]  events: Starting event system

[VioletHynes]

Looks good to me. Thanks for the write up and the fix!