Fix non-zero reference count for replica shard files in CompositeDirectory

[skumawat2025]

Describe the bug

When a new file is created in CompositeDirectory, its reference count is increased by 1 in the FileCache. This count is normally decreased when the file is uploaded to remote storage. However, for replica shards, a segment_n file is created but never uploaded, leaving its reference count at 1. This causes problems during index deletion, as some files can't be deleted due to non-zero references.

We need to evaluate two options:

• Prevent file creation on replica shards for CompositeDirectory.
• If files must be created on replica shards, ensure they don't have non-zero references in the FileCache.
  This issue affects clean index deletion and may lead to resource leaks if not addressed.

Meta Issue: #13149

Related component

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Expected behavior

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Additional Details

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