fix(deep_causality_algorithms): Fixed miri test config

[marvin-hansen]

Describe your changes

Fixed miri test config

Issue ticket number and link

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• All tests are passing when running make test?
• No errors or security vulnerabilities are reported by make check?

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Summary by cubic

Skip gate_tests when running under Miri by adding #[cfg(not(miri))]. This fixes Miri test failures while leaving normal test runs unchanged.

^{Written for commit 1dfbe46. Summary will update on new commits.}