### Elasticsearch Version

7.16.2, master

### Installed Plugins

no

### Java Version

_bundled_

### OS Version

Linux iZbp1dn0ktfed9mjoyuiajZ 5.10.84-10.2.al8.x86_64 #1 SMP Thu Feb 10 15:03:09 CST 2022 x86_64 x86_64 x86_64 GNU/Linux

### Problem Description

When put repository using PutRespository API for an existing repository, NullPointerException was thrown, short stack shows as below
```
1> java.lang.Exception: java.lang.NullPointerException: Cannot invoke "org.elasticsearch.repositories.Repository.getMetadata()" because "repository" is null
  1>   at org.elasticsearch.cluster.service.MasterService.innerExecuteTasks(MasterService.java:916) ~[main/:?]
  1>   at org.elasticsearch.cluster.service.MasterService.executeTasks(MasterService.java:871) ~[main/:?]
  1>   at org.elasticsearch.cluster.service.MasterService.runTasks(MasterService.java:253) [main/:?]
  1>   at org.elasticsearch.cluster.service.MasterService$Batcher.run(MasterService.java:153) [main/:?]
  1>   at org.elasticsearch.cluster.service.TaskBatcher.runIfNotProcessed(TaskBatcher.java:114) [main/:?]
  1>   at org.elasticsearch.cluster.service.TaskBatcher$BatchedTask.run(TaskBatcher.java:170) [main/:?]
  1>   at org.elasticsearch.common.util.concurrent.ThreadContext$ContextPreservingRunnable.run(ThreadContext.java:714) [main/:?]
  1>   at org.elasticsearch.common.util.concurrent.PrioritizedEsThreadPoolExecutor$TieBreakingPrioritizedRunnable.runAndClean(PrioritizedEsThreadPoolExecutor.java:260) [main/:?]
  1>   at org.elasticsearch.common.util.concurrent.PrioritizedEsThreadPoolExecutor$TieBreakingPrioritizedRunnable.run(PrioritizedEsThreadPoolExecutor.java:223) [main/:?]
  1>   at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136) [?:?]
  1>   at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635) [?:?]
  1>   at java.lang.Thread.run(Thread.java:833) [?:?]
```

### Steps to Reproduce

I've created an IT to reproduce this issue in [#85551](https://github.com/elastic/elasticsearch/pull/85551), steps can be described as following:
- put repository using `RestPutRepository` API and make sure non-master node failed to create repository.
- restart master let one of the previous non-master node become master
- put the same repository using the `RestPutRepository` API.

### Logs (if relevant)

_No response_
server/src/main/java/org/elasticsearch/repositories/RepositoriesService.java
* @param event cluster changed event
     */
    @Override
    public void applyClusterState(ClusterChangedEvent event) {
        try {
            final ClusterState state = event.state();
            final RepositoriesMetadata oldMetadata = event.previousState()
                .getMetadata()
                .custom(RepositoriesMetadata.TYPE, RepositoriesMetadata.EMPTY);
            final RepositoriesMetadata newMetadata = state.getMetadata().custom(RepositoriesMetadata.TYPE, RepositoriesMetadata.EMPTY);
            
            if (oldMetadata.equalsIgnoreGenerations(newMetadata)) {
                for (Repository repo : repositories.values()) {
                    repo.updateState(state);
                }
                return;
            }
            logger.trace("processing new index repositories for state version [{}]", event.state().version());
            Map<String, Repository> survivors = new HashMap<>();
            
            for (Map.Entry<String, Repository> entry : repositories.entrySet()) {
                if (newMetadata.repository(entry.getKey()) == null) {
                    logger.debug("unregistering repository [{}]", entry.getKey());
                    Repository repository = entry.getValue();
                    closeRepository(repository);
                    archiveRepositoryStats(repository, state.version());
                } else {
                    survivors.put(entry.getKey(), entry.getValue());
                }
            }