[C++] Use smallest term buffer for embedded IPC tests. #8223

Job	Run time
C++ GCC 6 (Ubuntu 20.04)	10m 15s
C++ GCC 7 (Ubuntu 20.04)	10m 1s
C++ GCC 8 (Ubuntu 20.04)	10m 3s
C++ GCC 9 (Ubuntu 20.04)	10m 50s
C++ GCC 10 (Ubuntu 20.04)	10m 20s
Java 17 (ubuntu-24.04)	5m 4s
Java 17 (windows-latest)	7m 37s
Java 17 (macos-latest)	6m 46s
Java 21 (ubuntu-24.04)	5m 13s
Java 21 (windows-latest)	9m 9s
Java Topology Tests (JDK 17, ubuntu-24.04)	2m 52s
Java 21 (macos-latest)	6m 32s
Java 23 (ubuntu-24.04)	5m 4s
Java 23 (windows-latest)	7m 51s
C++ Clang 19 debug build	10m 56s
C++ Clang 9 (Ubuntu 20.04)	11m 8s
Java 23 (macos-latest)	6m 54s
C++ Clang 10 (Ubuntu 20.04)	11m 42s
C++ Clang 13 (Ubuntu 24.04)	11m 21s
C++ Clang 11 (Ubuntu 20.04)	11m 29s
C++ Clang 14 (Ubuntu 24.04)	10m 50s
C++ GCC 11 (Ubuntu 24.04)	10m 29s
C++ Rocky 8 (10)	11m 26s
C++ Clang 12 (Ubuntu 20.04)	11m 34s
C++ Clang 15 (Ubuntu 24.04)	10m 30s
C++ GCC 12 (Ubuntu 24.04)	11m 43s
C++ Clang 16 (Ubuntu 24.04)	11m 10s
C++ GCC 13 (Ubuntu 24.04)	10m 59s
C++ Clang 17 (Ubuntu 24.04)	10m 54s
C++ GCC 14 (Ubuntu 24.04)	11m 37s
C++ MSVC (Windows)	11m 40s
C++ Xcode (macOS)	11m 41s
C++ Clang 18 (Ubuntu 24.04)	10m 35s
C++ Clang 19 (Ubuntu 24.04)	10m 51s
	5h 27m 6s

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