Fix baremetal build failures

[evedon]

Summary of changes

Fixed baremetal build failures (from nightly CI test).

• New test file asynchronous_dns_multi_ip.cpp was added in Add Getaddrinfo interface for multiple DNS adresses #11653 and is missing the MBED_CONF_RTOS_PRESENT guard.
• One include missing from kvstore static_tests (I haven't traced back why it was building before).

Impact of changes

Baremetal nightly tests should build successfully.

Migration actions required

Documentation

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Pull request type

[X] Patch update (Bug fix / Target update / Docs update / Test update / Refactor)
[] Feature update (New feature / Functionality change / New API)
[] Major update (Breaking change E.g. Return code change / API behaviour change)

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Test results

[] No Tests required for this change (E.g docs only update)
[X] Covered by existing mbed-os tests (Greentea or Unittest)
[] Tests / results supplied as part of this PR

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Reviewers

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[ciarmcom]

@evedon, thank you for your changes.
@ARMmbed/mbed-os-test @ARMmbed/mbed-os-storage @ARMmbed/mbed-os-ipcore @ARMmbed/mbed-os-maintainers please review.

[mbed-ci]

Test run: SUCCESS

Summary: 5 of 5 test jobs passed
Build number : 1
Build artifacts

[0xc0170]

I set this to 6.0.0 alpha1 to get tests passing for baremetal. cc @adbridge

[0xc0170]

As we havent merged anything since Friday (creation of this PR), my assumption is as stated above - baremetal build will pass tonight.