Fixed small perf overhead due to NPE for readItem returning 404

[FabianMeiswinkel]

Description

This PR fixes a performance regression introduced in 4.66.0 PR 43716 which results in unnecessary log messages when CosmosContainer .readItemor CosmosAsyncContainer.readItemreturns a 404 - NotFound

closes #43995

All SDK Contribution checklist:

• The pull request does not introduce [breaking changes]
• CHANGELOG is updated for new features, bug fixes or other significant changes.
• I have read the contribution guidelines.

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• Title of the pull request is clear and informative.
• There are a small number of commits, each of which have an informative message. This means that previously merged commits do not appear in the history of the PR. For more information on cleaning up the commits in your PR, see this page.

Testing Guidelines

• Pull request includes test coverage for the included changes.

[azure-sdk]

API change check

API changes are not detected in this pull request.

[jeet1995]

LGTM - thanks

[FabianMeiswinkel]

/azp run java - cosmos - tests

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[FabianMeiswinkel]

/azp run java - cosmos - tests

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[FabianMeiswinkel]

/azp run java - cosmos - spark

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[FabianMeiswinkel]

/check-enforcer override

[FabianMeiswinkel]

Flaky CF tests unrelated to this PR

[FabianMeiswinkel]

/azp run java - cosmos - spark

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).