fix: dont handle sigterm in middleware mode

[bluwy]

Description

Fix #7627

Additional context

Not sure if this is considered breaking, but we made similar changes in the past in minors, e.g. #4232

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What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

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[patak-dev]

About the breaking change bit, we could consider this a bug fix. Maybe we need an advanced section in the migration guide targeted at integration and framework maintainers so we can at least add a point about this change (like bug fixes that may require special attention)