check-abi: remove support for obsolete CMake library output location (src/libsecp256k1.so) #1738

1. 
   theStack commented at 10:01 pm on September 7, 2025: contributor

   The CMake library output location was changed from “src/” to “lib/” in PR #1553, supporting the old location (presumably done to avoid having users to reconfigure existing CMake builds for a temporary transition window) shouldn’t be necessary anymore.
2. check-abi: remove support for obsolete CMake library output location (src/libsecp256k1.so)

   The CMake library output location was changed from "src/" to "lib/"
   in PR #1553, supporting the old location shouldn't be necessary anymore.

   7ebaa134a7
3. real-or-random approved
4. 
   real-or-random commented at 6:52 am on September 8, 2025: contributor

   utACK https://github.com/bitcoin-core/secp256k1/pull/1738/commits/7ebaa134a758946f703eaba02fe19cf5a0598490
5. real-or-random added the label assurance on Sep 8, 2025
6. real-or-random added the label build on Sep 8, 2025
7. real-or-random added the label tweak/refactor on Sep 8, 2025
8. real-or-random merged this on Sep 9, 2025
9. real-or-random closed this on Sep 9, 2025

   ---

10. theStack deleted the branch on Sep 9, 2025
11. 
    hebasto commented at 1:08 pm on September 9, 2025: member

    Post-merge ACK 7ebaa134a758946f703eaba02fe19cf5a0598490. Tested on Ubuntu 25.04.

Contributors
theStack real-or-random hebasto

Labels
assurance build tweak/refactor