Consider the status of forbidden when checking that the registry is a…

[HelloSmallSnail]

…vailable

What is the purpose of the change

提供者集群停机，消费者调用过程中需要切换zookeeper时，可能会发生forbidden异常，此提交修复该问题。
请参考issue：#7945

Brief changelog

在RegistryDirectory的isAvailable()方法中，增加对forbidden状态的判断

Verifying this change

Checklist

• Make sure there is a GitHub_issue field for the change (usually before you start working on it). Trivial changes like typos do not require a GitHub issue. Your pull request should address just this issue, without pulling in other changes - one PR resolves one issue.
• Each commit in the pull request should have a meaningful subject line and body.
• Write a pull request description that is detailed enough to understand what the pull request does, how, and why.
• Check if is necessary to patch to Dubbo 3 if you are work on Dubbo 2.7
• Write necessary unit-test to verify your logic correction, more mock a little better when cross module dependency exist. If the new feature or significant change is committed, please remember to add sample in dubbo samples project.
• Add some description to dubbo-website project if you are requesting to add a feature.
• GitHub Actions works fine on your own branch.
• If this contribution is large, please follow the Software Donation Guide.

[xiaoheng1]

Hello, please merge master, and then try again to see if ut can pass

[codecov-commenter]

Codecov Report

Merging #7946 (50c0474) into master (ab4ced5) will decrease coverage by 0.01%.
The diff coverage is 100.00%.

@@             Coverage Diff              @@
##             master    #7946      +/-   ##
============================================
- Coverage     60.85%   60.84%   -0.02%     
  Complexity      491      491              
============================================
  Files          1089     1089              
  Lines         43877    43877              
  Branches       6412     6412              
============================================
- Hits          26703    26697       -6     
- Misses        14210    14214       +4     
- Partials       2964     2966       +2     

Impacted Files	Coverage Δ
.../dubbo/registry/integration/RegistryDirectory.java	76.17% <100.00%> (ø)
...ng/transport/dispatcher/all/AllChannelHandler.java	89.65% <0.00%> (-6.90%)	⬇️
.../apache/dubbo/remoting/transport/AbstractPeer.java	58.69% <0.00%> (-4.35%)	⬇️
...etadata/report/support/AbstractMetadataReport.java	57.28% <0.00%> (-2.43%)	⬇️
...ting/zookeeper/curator/CuratorZookeeperClient.java	69.54% <0.00%> (-1.15%)	⬇️
.../dubbo/remoting/transport/netty4/NettyChannel.java	61.38% <0.00%> (-1.00%)	⬇️
...he/dubbo/registry/multicast/MulticastRegistry.java	70.23% <0.00%> (+0.93%)	⬆️
...e/dubbo/remoting/transport/netty4/NettyClient.java	71.01% <0.00%> (+1.44%)	⬆️
...port/identifier/BaseServiceMetadataIdentifier.java	60.71% <0.00%> (+3.57%)	⬆️
...rg/apache/dubbo/remoting/utils/PayloadDropper.java	92.30% <0.00%> (+15.38%)	⬆️

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[AlbumenJ]

LGTM.