fix: use a tmp file and rename to prevent a possible race condition

[jvillafanez]

Description

Use a temporary file and then rename in order to prevent a race condition. This should help to prevent getting thumbnails with 0 byte content or with partial content.
According to the documentation, the won't be name collisions in the FS with the temporary files, so every thumbnail will be written into a unique file before trying to rename it to the final file (0 byte or partial content shouldn't happen).

NOTE: The previous os.Create call creates a file with 0666 permissions. The new os.CreateTemp creates the file with 0600 permissions, so the new thumbnails will have different permissions on the FS. This shouldn't cause problems though.

Related Issue

#10684

Motivation and Context

This increases the stability of the system by preventing the error from happening.

How Has This Been Tested?

Basic case has been tested manually to ensure the code doesn't break anything.
Error reproduction is very difficult because it's a race condition, but the error message should clarify what's happening.

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Technical debt
• Tests only (no source changes)

Checklist:

• Code changes
• Unit tests added
• Acceptance tests added
• Documentation ticket raised:

[update-docs]

Thanks for opening this pull request! The maintainers of this repository would appreciate it if you would create a changelog item based on your changes.

[mmattel]

@jvillafanez pls dont forget to add a changelog 😃

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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