GH-49434: [C++][CI] Add golden integration files to IPC file fuzz corpus

[pitrou]

Rationale for this change

For the IPC stream fuzzer, we are adding the golden integration files to the seed corpus, but we are currently not doing the same thing for the file fuzzer.

What changes are included in this PR?

1. Add golden IPC integration files to the IPC file fuzzer seed corpus
2. Minor cosmetic changes to the C++ test script, to make the output slightly less bulky (no functional difference)

Are these changes tested?

Yes, by existing CI tests.

Are there any user-facing changes?

No.

• GitHub Issue: [C++][CI] Add golden integration files to IPC file fuzz corpus #49434

[pitrou]

@github-actions crossbow submit -g cpp

[github-actions]

Revision: b7752de

Submitted crossbow builds: ursacomputing/crossbow @ actions-d059852edf

Task	Status
example-cpp-minimal-build-static
example-cpp-minimal-build-static-system-dependency
example-cpp-tutorial
test-build-cpp-fuzz
test-conda-cpp
test-conda-cpp-valgrind
test-debian-13-cpp-amd64
test-debian-13-cpp-i386
test-debian-experimental-cpp-gcc-15
test-fedora-42-cpp
test-ubuntu-22.04-cpp
test-ubuntu-22.04-cpp-20
test-ubuntu-22.04-cpp-bundled
test-ubuntu-22.04-cpp-emscripten
test-ubuntu-22.04-cpp-no-threading
test-ubuntu-24.04-cpp
test-ubuntu-24.04-cpp-bundled-offline
test-ubuntu-24.04-cpp-gcc-13-bundled
test-ubuntu-24.04-cpp-gcc-14
test-ubuntu-24.04-cpp-minimal-with-formats
test-ubuntu-24.04-cpp-thread-sanitizer

[pitrou]

@github-actions crossbow submit wheel-macos-monterey-cp313-cp313-arm64

[github-actions]

Revision: ce494fc

Submitted crossbow builds: ursacomputing/crossbow @ actions-e6089ea28d

Task	Status
wheel-macos-monterey-cp313-cp313-arm64

[pitrou]

This PR fixes the macOS wheel build issues @raulcd