Merge bitcoin/bitcoin#24754: build: specify cmake build dir for multiprocess depends build

7c218dacd0e9602b8f755be42e96c49706f96305 build: specify cmake build dir for multiprocess depends build (fanquake)

Pull request description:

  When no build dir is specified, cmake will warn:
  ```bash
  Preprocessing libmultiprocess...
  Configuring libmultiprocess...
  CMake Warning:
    No source or binary directory provided.  Both will be assumed to be the
    same as the current working directory, but note that this warning will
    become a fatal error in future CMake releases.
  ```

  It's unclear if this will actually ever become an error, but it's also easy
  enough to just supply the directory, and save this maybe breaking in
  future.

ACKs for top commit:
  ryanofsky:
    Code review ACK 7c218dacd0e9602b8f755be42e96c49706f96305. I guess the purpose of the warning is to encourage people not to build in the source directory, but reasons for encouraging this don't really apply to the depends build system, so it is appropriate to disable the warning.
  hebasto:
    ACK 7c218dacd0e9602b8f755be42e96c49706f96305, tested on Ubuntu 22.04.

Tree-SHA512: 6904f2095fe62cead4abc644ec888c5d836e54a3c0b2a84c467029116e5d14eba35190570acaa23c6831aed9a4a65898134480cc46cdb141279ec0dc6f534d5f

0 files changed, 0 insertions, 0 deletions