Fix upload limit. Fixes #3156

[xrhstoskap]

Description

Fix large file upload failures caused by mismatched backend limits.

This PR fixes an issue where file uploads larger than 50MB would silently fail.
Although nginx was configured to allow uploads up to 100MB, Django backend settings
(DATA_UPLOAD_MAX_MEMORY_SIZE and FILE_UPLOAD_MAX_MEMORY_SIZE) were limited to 50MB,
causing requests to be rejected before processing.

Fixes #3156

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What changed

• Increased DATA_UPLOAD_MAX_MEMORY_SIZE
• Increased FILE_UPLOAD_MAX_MEMORY_SIZE
• Aligned Django backend upload limits with the nginx configuration (100MB)

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Type of change

• 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 not work as expected).

Checklist

• I have read and understood the rules about how to Contribute to this project
• The pull request is for the branch develop
• Linters (Black, Flake, Isort) gave 0 errors.
• I have added tests for the feature/bug I solved (see tests folder).

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Notes

• This change only affects backend upload limits.
• No impact on existing APIs or plugin behavior.
• Successfully tested by uploading and processing a ~75MB file.

[fgibertoni]

Hey, please read the full contribution guidelines and adjust the PR accordingly, thanks.