Fix HoareOptimizer cache recursion and add regression test

[littlebullGit]

Fixes #14969

Summary

• Fix [HoareOptimizer] recursion when cache entries become stale.
• Add regression test covering issue HoareOptimizer crashes with ValueError: DAGOpNode is not in list #14969.
• Document the fix in the 2.3 release notes.

Details and comments

• I have added the tests to cover my changes.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.

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[coveralls]

Pull Request Test Coverage Report for Build 18205371620

Details

• 10 of 10 (100.0%) changed or added relevant lines in 1 file are covered.
• 21 unchanged lines in 4 files lost coverage.
• Overall coverage decreased (-0.01%) to 88.223%

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Files with Coverage Reduction	New Missed Lines	%
crates/circuit/src/parameter/parameter_expression.rs	1	81.99%
crates/circuit/src/parameter/symbol_expr.rs	1	72.82%
crates/qasm2/src/lex.rs	7	91.77%
crates/qasm2/src/parse.rs	12	96.62%

Totals
Change from base Build 18200109104:	-0.01%
Covered Lines:	93109
Relevant Lines:	105538

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💛 - Coveralls