test-lib.sh: set GIT_TRACE2_EVENT_NESTING
The GIT_TRACE2_EVENT feed has a limited nesting depth to avoid overloading the feed when recursing into deep paths while adding more nested regions. Some tests use the GIT_TRACE2_EVENT feed to look for internal events, ensuring that intended behavior is happening. One such example is in t4216-log-bloom.sh which looks for a statistic given as a trace2_data_intmax() call. This test started failing under '-x' with 2ca245f8be5 (csum-file.h: increase hashfile buffer size, 2021-05-18) because the change in stderr triggered the progress API to create an extra trace2 region, ejecting the statistic. This change increases the value of GIT_TRACE2_EVENT_NESTING across the entire test suite to avoid errors like this. Future changes will remove custom assignments of GIT_TRACE2_EVENT_NESTING from some test scripts that were aware of this limitation. Reported-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>