Fix sdk/spring/README.md not found error in non-spring ci pipelines

[saragluna]

Description

We added the empty Javadoc and sources jar files in #28988, but it will use the README file in sdk/spring folder, which will be an issue when build from source pipelines run in the non-spring service directory, for the sparse checkout won't check out the sdk/spring folder, like this failure. This PR will fix this issue by disabling throwing exceptions when the file can't be found. This PR will also fix the bug of not cleaning the sourceTemp folder for each run.

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.

[saragluna]

/azp run java - resourcemanager - ci

[azure-pipelines]

Azure Pipelines could not run because the pipeline triggers exclude this branch/path.

[azure-sdk]

API change check

API changes are not detected in this pull request.

[saragluna]

/azp run java - resourcemanager - ci

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[saragluna]

The resource manager build passed.

[XiaofeiCao]

Thanks!

[chenrujun]

Maybe we should update the sparse checkout instead of setting failonerror="false" here.

Setting failonerror="false" may cause the released javadoc / sourcejar does not contains README.md.

We should avoid uncertain behavior.

[saragluna]

I think it's okay, the sdk/spring/REAME.md will always be there, and what we want to achieve here is to avoid exceptions when sparse checkout does not include the sdk/spring/README.md file.

[saragluna]

What we also want to avoid is adding a README.md in each starter's folder.

[saragluna]

And even if we ship some Javadoc and source jar files without the README, I think it'll still be ok. The starters don't have any source code or Javadoc.

[chenrujun]

The key point is We should avoid uncertain behavior.

Consider this conversation:

Customer: Does the source jar contains README?
We: We are not sure.

That's not professional.

[chenrujun]

I'll approve this PR to quick fix pipeline failure.

But whether we should contain s README.md in source-jar and java-doc-jar need more discussion

[saragluna]

@chenrujun, you can help create another PR to remove the README file from the Javadoc and sources jar files.

[saragluna]

But I think this will provide more context on what's a usable Javadoc jar file, like this https://azuresdkdocs.blob.core.windows.net/$web/java/azure-storage-blob/12.16.1/index.html.

• Build of azure-aot-graalvm-support-netty which contains no Javadoc: https://dev.azure.com/azure-sdk/internal/_build/results?buildId=1493631&view=logs&j=318930d9-f237-5278-20ae-eab91598c7d0&t=713fface-1568-5a4a-52a5-48aa8430b3be
• Build of azure-storage-blob which contains Javadoc: https://dev.azure.com/azure-sdk/internal/_build/results?buildId=1566962&view=logs&j=318930d9-f237-5278-20ae-eab91598c7d0&t=713fface-1568-5a4a-52a5-48aa8430b3be

I have no preference for whether our starter Javadoc jar must have a README.md file or not, but if removing the README logic could simplify our pom files, it would be great and worth a try.