build: note that sysctl was removed from Linux #33111

1. 
   fanquake commented at 10:07 am on August 1, 2025: member

   https://kernelnewbies.org/Linux_5.5#Core_.28various.29.

   The checks need to hang around until we no-longer support kernels older than 5.5.

2. build: note that sysctl was removed from Linux

   https://kernelnewbies.org/Linux_5.5#Core_.28various.29.
   
   The checks need to hang around until we no-longer support kernels older
   than 5.5.

   a78dfd7cee
3. DrahtBot added the label Build system on Aug 1, 2025
4. 
   DrahtBot commented at 10:07 am on August 1, 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/33111.

   Reviews

   See the guideline for information on the review process.

   Type	Reviewers
   ACK	janb84

   If your review is incorrectly listed, please react with 👎 to this comment and the bot will ignore it on the next update.

5. 
   janb84 commented at 2:12 pm on August 1, 2025: contributor

   ACK a78dfd7cee4d25a455bd35c5ef2bd7d5cd2072b0

   PR changes the error message of sysctl.h when used on linux to reflect current state (from deprecated to removed)

Contributors
fanquake DrahtBot janb84

Labels
Build system