Update minisketch subtree and switch to its build script #32856

1. 
   hebasto commented at 10:17 am on July 2, 2025: member

   This PR:

   1. Updates the minisketch subtree to latest upstream, which includes:

      • https://github.com/bitcoin-core/minisketch/pull/75

   2. Switches to minisketch upstream build system.

2. Squashed 'src/minisketch/' changes from ea8f66b1ea..f74b7e2bc2

   f74b7e2bc2 Merge sipa/minisketch#75: build: Introduce CMake-based build system
   850cc868d5 ci: Add GHA workflow with native Windows job
   40d56708c8 doc: Add "Building with CMake" section to `README.md`
   a0c86c79a7 build: Add CMake-based build system
   
   git-subtree-dir: src/minisketch
   git-subtree-split: f74b7e2bc2e5e1a1360927934521216bee5f345c

   b1b208f724
3. Update minisketch subtree to latest upstream ec5c6a1163
4. cmake: Switch to `minisketch` upstream build system a6b48f009f
5. hebasto added the label Build system on Jul 2, 2025
6. 
   DrahtBot commented at 10:17 am on July 2, 2025: contributor

   The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.

   Code Coverage & Benchmarks

   For details see: https://corecheck.dev/bitcoin/bitcoin/pulls/32856.

   Reviews

   See the guideline for information on the review process. A summary of reviews will appear here.

7. 
   hebasto commented at 10:18 am on July 2, 2025: member

   This PR concludes the joint efforts of @sipa, @purpleKarrot, @theuni, and me.

Contributors
hebasto DrahtBot

Labels
Build system