feat: Add optional path var for instance level bucket path

[levinandrew]

Below the TF plan are the updated env vars

TF plan:

Terraform will perform the following actions:

  # module.wandb.module.app_aks.azurerm_kubernetes_cluster.default will be updated in-place
  ~ resource "azurerm_kubernetes_cluster" "default" {
...

      ~ default_node_pool {
            name                         = "default"
            tags                         = {}
            # (24 unchanged attributes hidden)

          - upgrade_settings {
              - drain_timeout_in_minutes      = 0 -> null
              - max_surge                     = "10%" -> null
              - node_soak_duration_in_minutes = 0 -> null
            }
        }

        # (6 unchanged blocks hidden)
    }

  # module.wandb.module.wandb.helm_release.wandb will be updated in-place
  ~ resource "helm_release" "wandb" {
        id                         = "wandb-cr"
      ~ metadata                   = [
          - {
              - app_version    = "1.0.0"
              - chart          = "wandb-cr"
              - first_deployed = 1724465197
              - last_deployed  = 1724465197
              - name           = "wandb-cr"
              - namespace      = "default"
              - notes          = ""
              - revision       = 1
              - values         = jsonencode(
                    {
                      - name = "wandb"
                      - spec = <<-EOT
                            "values":
                              "app":
...
                                "bucket":
                                  "accessKey": "<redacted>"
                                  "name": "levinaztwostorage"
                                  "path": "wandb"
                                  "provider": "az"
                                "cloudProvider": "azure"
  ...
                        EOT
                    }
                )
              - version        = "0.1.0"
            },
        ] -> (known after apply)
        name                       = "wandb-cr"
        # (26 unchanged attributes hidden)

...

        # (1 unchanged block hidden)
    }

Plan: 0 to add, 2 to change, 0 to destroy.

Updated env vars:

wandb@wandb-app-6cc8d6b764-p55qm:~$ env | grep -i nested
BUCKET=az://levinaztwostorage/wandb/nested/path
    "store": "az://levinaztwostorage/wandb/nested/path",
OVERFLOW_BUCKET_ADDR=az://levinaztwostorage/wandb/nested/path
GORILLA_FILE_STORE=az://levinaztwostorage/wandb/nested/path
GORILLA_STORAGE_BUCKET=az://levinaztwostorage/wandb/nested/path

[jsbroks]

This PR is included in version 2.14.0 🎉