Auto merge of #24374 - Tugdual:tug-by-ref-argument, r=jdm

Pass argument by reference to CacheKey constructor

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Argument now passed by reference, and clone() removed when calling
constructor.

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- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #24353 (GitHub issue number if applicable)

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- [x] These changes do not require tests because @jdm said it only need to build

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