refactor: Remove unused HaveKey and HaveWatchOnly #32476

1. 
   maflcko commented at 7:46 AM on May 13, 2025: member

   removes some dead code

2. Remove HaveKey helper, unused after sethdseed removal fa7b7f796a
3. Remove unused LegacyDataSPKM::HaveWatchOnly() fabdc5ad06
4. 
   DrahtBot commented at 7:46 AM on May 13, 2025: contributor

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   Code Coverage & Benchmarks

   For details see: https://corecheck.dev/bitcoin/bitcoin/pulls/32476.

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5. DrahtBot added the label Refactoring on May 13, 2025
6. 
   maflcko commented at 7:47 AM on May 13, 2025: member

   (follow-up to #32438)

7. fanquake requested review from Sjors on May 13, 2025
8. 
   Sjors commented at 9:32 AM on May 13, 2025: member

   utACK fabdc5ad06bce8cd3b0e525071d10f616a30bb04

9. fanquake merged this on May 13, 2025
10. fanquake closed this on May 13, 2025

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11. maflcko deleted the branch on May 13, 2025
12. stickies-v referenced this in commit 772a33e052 on May 23, 2025
13. sedited referenced this in commit cb3cd9b8b9 on May 29, 2025
14. yuvicc referenced this in commit 069643f094 on Jul 6, 2025
15. bug-castercv502 referenced this in commit 2858098810 on Sep 28, 2025
16. Kino1994 referenced this in commit c0c26a4989 on Jun 28, 2026
17. BigcoinBGC referenced this in commit 63ae353b83 on Jun 30, 2026
18. bitcoin locked this on Jul 30, 2026

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