chore: change screenshot image type from JPEG to WEBP

[marandaneto]

💡 Motivation and Context

File Info
• Resolution: 1080×2400
• MIME type: image/octet-stream
• Extension: bin
• Size: 6.69 KB
• Download: image.bin
WEBP_LOSSY

File Info
• Resolution: 1080×2400
• MIME type: image/octet-stream
• Extension: bin
• Size: 310.68 KB
• Download: image.bin
WEBP_LOSSLESS

File Info
• Resolution: 1080×2400
• MIME type: image/octet-stream
• Extension: bin
• Size: 6.69 KB
• Download: image.bin
WEBP or WEBP_LOSSY

File Info
• Resolution: 1080×2400
• MIME type: image/png
• Extension: png
• Size: 20.45 KB
• Download: image.png
• Bit depth: 8
PNG

File Info
• Resolution: 1080×2400
• MIME type: image/jpeg
• Extension: jpg
• Size: 20.25 KB
• Download: image.jpg
• Channels: 3
• Bit depth: 8
JPEG

Also this https://github.com/PostHog/posthog-ios/blob/5dceb9b86f6c65c1dcc6d18ae97e1face7236636/PostHog/Replay/PostHogReplayIntegration.swift#L178
Since the base64 image is lossy and loses all metadata, we won't be resending a new snapshot in case nothing changes in the generated image.

💚 How did you test it?

📝 Checklist

• I reviewed the submitted code.
• I added tests to verify the changes.
• I updated the docs if needed.
• No breaking change or entry added to the changelog.

[pauldambra]

🚀