Reoccurring null in LockableResourcesManager resources

### Jenkins and plugins versions report

Environment

```text
Jenkins: 2.426.2
OS: Linux - 5.15.0-1064-azure
Java: 17.0.9 - Eclipse Adoptium (OpenJDK 64-Bit Server VM)
lockable-resources:1218.va_3dd45e2b_fa_7
```

### What Operating System are you using (both controller, and any agents involved in the problem)?

Jenkins is running in a container on Ubuntu 22

### Reproduction steps

Unfortunately I do not have exact steps to reproduce the issue. I have a number of jobs that use lockable resources, so resources are locked/unlocked continuously minimum few times a minute. I've observed that every few days somehow a *null* is added to LockableResourcesManager *resources* list. This breaks not only the plugin (any call to step lock throws exception), but also global Jenkins configuration and the only option to fix it, is to directly replace *resources* list in LockableResourcesManager.
I'm not using any advanced features of this plugin, only simple step `lock('lock-name') { }`
I was tryin to find any logs from when this null was added, but I didn't find any.
I doubt it matters, but in my case job name is often used as resource name.

### Expected Results

I don't know how is that even possible that a *null* resource is added to the LockableResourcesManager.resources, but I would expect that LockableResourcesManager should be able to remove it as clearly invalid entry.

### Actual Results

I've observed two logs in case of failure (but I'm not sure why there are two variants) - both often appear mixed in log of the same job, that attempts to lock always the same resource.

```
Trying to acquire lock on []
[Pipeline] // lock
[Pipeline] End of Pipeline
java.lang.NullPointerException
Finished: FAILURE
```

and longer one:

```
[Pipeline] lock
Trying to acquire lock on []
[Pipeline] // lock
[Pipeline] End of Pipeline
Also: org.jenkinsci.plugins.workflow.actions.ErrorAction$ErrorId: a326e53e-1b63-49e1-9293-60b260f97d14
java.lang.NullPointerException: Cannot invoke "org.jenkins.plugins.lockableresources.LockableResource.getName()" because "r" is null
at org.jenkins.plugins.lockableresources.LockableResourcesManager.fromName(LockableResourcesManager.java:272)
at org.jenkins.plugins.lockableresources.LockableResourcesManager.resourceExist(LockableResourcesManager.java:292)
at org.jenkins.plugins.lockableresources.LockableResourcesManager.addResource(LockableResourcesManager.java:803)
at org.jenkins.plugins.lockableresources.LockableResourcesManager.createResource(LockableResourcesManager.java:753)
at org.jenkins.plugins.lockableresources.LockStepExecution.start(LockStepExecution.java:55)
at org.jenkinsci.plugins.workflow.cps.DSL.invokeStep(DSL.java:323)
at org.jenkinsci.plugins.workflow.cps.DSL.invokeMethod(DSL.java:196)
at org.jenkinsci.plugins.workflow.cps.CpsScript.invokeMethod(CpsScript.java:124)
at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.call(PogoMetaClassSite.java:47)
at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:47)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:116)
at com.cloudbees.groovy.cps.sandbox.DefaultInvoker.methodCall(DefaultInvoker.java:20)
at org.jenkinsci.plugins.workflow.cps.LoggingInvoker.methodCall(LoggingInvoker.java:105)
at discardOtherConcurrent.call(discardOtherConcurrent.groovy:6)
at discardOtherConcurrent.call(discardOtherConcurrent.groovy)
at WorkflowScript.run(WorkflowScript:32)
at ___cps.transform___(Native Method)
at com.cloudbees.groovy.cps.impl.ContinuationGroup.methodCall(ContinuationGroup.java:90)
at com.cloudbees.groovy.cps.impl.FunctionCallBlock$ContinuationImpl.dispatchOrArg(FunctionCallBlock.java:116)
at com.cloudbees.groovy.cps.impl.FunctionCallBlock$ContinuationImpl.fixArg(FunctionCallBlock.java:85)
at jdk.internal.reflect.GeneratedMethodAccessor247.invoke(Unknown Source)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:568)
at com.cloudbees.groovy.cps.impl.ContinuationPtr$ContinuationImpl.receive(ContinuationPtr.java:72)
at com.cloudbees.groovy.cps.impl.ClosureBlock.eval(ClosureBlock.java:46)
at com.cloudbees.groovy.cps.Next.step(Next.java:83)
at com.cloudbees.groovy.cps.Continuable$1.call(Continuable.java:152)
at com.cloudbees.groovy.cps.Continuable$1.call(Continuable.java:146)
at org.codehaus.groovy.runtime.GroovyCategorySupport$ThreadCategoryInfo.use(GroovyCategorySupport.java:136)
at org.codehaus.groovy.runtime.GroovyCategorySupport.use(GroovyCategorySupport.java:275)
at com.cloudbees.groovy.cps.Continuable.run0(Continuable.java:146)
at org.jenkinsci.plugins.workflow.cps.SandboxContinuable.access$001(SandboxContinuable.java:18)
at org.jenkinsci.plugins.workflow.cps.SandboxContinuable.run0(SandboxContinuable.java:51)
at org.jenkinsci.plugins.workflow.cps.CpsThread.runNextChunk(CpsThread.java:187)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.run(CpsThreadGroup.java:423)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:331)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:295)
at org.jenkinsci.plugins.workflow.cps.CpsVmExecutorService$2.call(CpsVmExecutorService.java:97)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at hudson.remoting.SingleLaneExecutorService$1.run(SingleLaneExecutorService.java:139)
at jenkins.util.ContextResettingExecutorService$1.run(ContextResettingExecutorService.java:28)
at jenkins.security.ImpersonatingExecutorService$1.run(ImpersonatingExecutorService.java:68)
at jenkins.util.ErrorLoggingExecutorService.lambda$wrap$0(ErrorLoggingExecutorService.java:51)
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:539)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
at java.base/java.lang.Thread.run(Thread.java:840)
Finished: FAILURE
```

### Anything else?

_No response_

### Are you interested in contributing a fix?

_No response_