fix: image processing and adjust client initializing

[Pymetheus]

Description

Convert images in RGBA/P mode to RGB before resizing to avoid format errors during processing. Initialize Twitter/Bluesky API clients only when their features are enabled. Add handling for ImageProcessingError in the bot's publish flow and slightly adjust MIN_SLEEP_TIME/MAX_SLEEP_TIME values. Also add stsci.edu to dev space_handles in the dev config.

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Code refactoring
• Performance improvement
• Test addition or update

Related Issue

Avoiding format errors during processing

Changes Made

• Convert images in RGBA/P mode to RGB before resizing to avoid format errors during processing.
• Initialize Twitter/Bluesky API clients only when their features are enabled.
• Adjust MIN_SLEEP_TIME/MAX_SLEEP_TIME values.

Testing

Describe how you tested your changes:

• Unit tests pass
• Integration tests pass
• Manual testing performed

Screenshots (if applicable)

Add screenshots to help explain your changes.

Checklist

• My code follows the project's style guidelines
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have updated the documentation accordingly
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes