Break tree_operations test into shards. #4015

Job	Run time
KytheVerification	11m 16s
ClangTidy	19m 2s
KytheXrefs	0s
x86_64 test	12m 51s
arm64 test	11m 54s
x86_64 test-nortti	13m 42s
x86_64 test-c++20	15m 53s
x86_64 test-c++23	16m 2s
x86_64 smoke-test	14m 56s
arm64 smoke-test	14m 7s
x86_64 smoke-test-analyzer	20m 9s
arm64 smoke-test-analyzer	19m 1s
x86_64 asan	23m 29s
x86_64 asan-clang	17m 14s
x86_64 compile	11m 32s
arm64 compile	7m 28s
x86_64 compile-clang	7m 21s
arm64 compile-clang	7m 11s
x86_64 compile-static	7m 9s
arm64 compile-static	8m 11s
x86_64 compile-static-clang	7m 17s
arm64 compile-static-clang	7m 27s
x86_64 coverage	18m 13s
x86_64 clean	7m 4s
arm64 clean	6m 50s
MacOsBuildDevTools	13m 7s
MacOsBuild	31m 9s
Generate Build matrix	4s
PrepareVSPlugin	2m 10s
VerifyFormatting	1m 43s
WindowsBuild	42m 53s
Build ·${{ matrix.arch }}:${{ matrix.os }}:${{ matrix.ver }}${{ (((matrix.link == 'static') && ':static') \|\| '') }}	0s
Build and deploy GitHub pages	10s
📦 Release	0s
	6h 36m 35s

Provide feedback