Fix miner panic on GLFW init failure

[DaMatrix]

Description

This fixes a stupid oversight in the OpenGL miner implementation: the default GLFW initialization callback causes a panic on failure, which caused the entire worker thread running the miner to exit prematurely.

Changelog

• Make GLFW initialization error handling more robust by relaying any errors up to the caller
• Added a .dockerignore file configured to ignore the irrelevant scratch files present in a development environment, because sending 7GiB of data to the docker build context seems somewhat excessive and makes stuff significantly slower

Type of Change

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• Bug fix
• New feature
• Enhancement or optimization
• Documentation update
• Other (please specify)

Checklist

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• I have tested the changes locally and they work as expected.
• I have added necessary documentation or updated existing documentation.
• My code follows the project's coding standards and style guidelines.
• I have added/updated relevant tests to ensure the changes are properly covered.
• I have checked for and resolved any merge conflicts.
• My commits have clear and descriptive messages.

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Additional Context (if applicable)

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Related Issues (if applicable)

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