Remove qiskit-bot notification rule for rust changes (backport #13198)

[mergify[bot]]

Summary

We previously had a qiskit-bot notification trigger for changes to the rust source or cargo configuration that would list myself and @kevinhartman as the relevant reviewers. While this is still true, as Qiskit is now >16% Rust (by lines of code, excluding tests) and that ratio will only grow over time, the two of us are hardly the only people worth calling out specifically as reviewers of rust code. Instead of expanding the list to include the entirety of the terra-core team individually this just removes the custom notification rule and opts to fallback to the default terra-core entry.

Details and comments

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This is an automatic backport of pull request #13198 done by Mergify.

[qiskit-bot]

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One or more of the following people are relevant to this code:

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[coveralls]

Pull Request Test Coverage Report for Build 10960512499

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 19 unchanged lines in 3 files lost coverage.
• Overall coverage decreased (-0.02%) to 89.758%

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Files with Coverage Reduction	New Missed Lines	%
crates/qasm2/src/expr.rs	1	94.02%
crates/qasm2/src/lex.rs	6	91.98%
crates/qasm2/src/parse.rs	12	97.15%
<!--	Total:	19		-->

Totals
Change from base Build 10959931349:	-0.02%
Covered Lines:	66877
Relevant Lines:	74508

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💛 - Coveralls