Kubernetes DiscoveryClient unavailable during Vault Bootstrap Configuration

Describe the bug
Parameter 0 of method vaultServerInstanceProvider in org.springframework.cloud.vault.config.DiscoveryClientVaultBootstrapConfiguration required a bean of type 'org.springframework.cloud.client.discovery.DiscoveryClient' that could not be found.

Error log
error.log

spring-boot
org.springframework.boot:spring-boot:2.4.5-SNAPSHOT
spring-cloud-vault
org.springframework.cloud:spring-cloud-starter-vault-config:3.0.3-SNAPSHOT
spring-cloud-kubernetes
org.springframework.cloud:spring-cloud-kubernetes-fabric8-discovery:2.0.3-SNAPSHOT

bootstrap.yaml

spring:
  application:
    name: vault-kubernetes-application
  cloud:
    discovery:
      enabled: true
    kubernetes:
      config:
        enabled: true
        enable-api: true
        sources:
          - name: vault-kubernetes-application
      discovery:
        enabled: true
        primary-port-name: backend
        catalog-services-watch:
          enabled: true
          catalog-services-watch: 5000
    vault:
      authentication: kubernetes
      connection-timeout: 5000
      read-timeout: 15000
      discovery:
        enabled: true
        service-id: vault
      kv:
        application-name: vault-kubernetes-application
        backend: backend-secrets
        enabled: true
      kubernetes:
        role: backend-read-role
        kubernetes-path: kubernetes

Sample
sample.zip

Start with the bootstrap.yaml configuration, error.log, and sample.zip, then inspect DiscoveryClientVaultBootstrapConfiguration and its vaultServerInstanceProvider entry point. Reproduce the startup failure and verify that a Kubernetes DiscoveryClient is available during Vault bootstrap configuration.