Merge bitcoin/bitcoin#27503: Bump to 25.99 and remove release note fragments

9c24826 doc: Remove 25.0 release note fragments (Andrew Chow)
088a93d build: Bump to 25.99 (Andrew Chow)

Pull request description:

  Pre-25.x branch off version bump and release note fragments removal.

  The 25.0 draft release notes are in the dev wiki: https://github.com/bitcoin-core/bitcoin-devwiki/wiki/25.0-Release-Notes-Draft

ACKs for top commit:
  fanquake:
    ACK 9c24826

Tree-SHA512: f7c7b04aa904e946bc672b5b07082a819b9d76ebccda0838bc27d0e6179cfb88b8f110500d5ea815f711580916bcfa0275774ec50a7298a4c66e645647111125

Author: fanquake

configure.ac

@@ -1,5 +1,5 @@
 AC_PREREQ([2.69])
-define(_CLIENT_VERSION_MAJOR, 24)
+define(_CLIENT_VERSION_MAJOR, 25)
 define(_CLIENT_VERSION_MINOR, 99)
 define(_CLIENT_VERSION_BUILD, 0)
 define(_CLIENT_VERSION_RC, 0)