Update default stack version to 8.10.1

[mrodm]

This PR updates the default stack version to 8.10.1

In tests, it has also been updated to 8.11.0-SNAPSHOT the target test-stack-command-8x

Additional:

• it has been updated the debug message about version cached:

#Before
2023/09/19 21:51:09 DEBUG latest version (cached): &{v0.87.1 https://github.com/elastic/elastic-package/releases/tag/v0.87.1 2023-09-19 21:38:49.561771091 +0200 CEST}
#Now
2023/09/20 12:39:13 DEBUG latest version (cached): v0.87.1. Download from: https://github.com/elastic/elastic-package/releases/tag/v0.87.1 (Timestamp 2023-09-20 12:30:26.593876097 +0200 CEST)

[elasticmachine]

💚 Build Succeeded

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• Commit: 596838f

cc @mrodm