message: exclude test_install from header formatting
diff: source .github/bot-base.sh
  EXTENSION_REGEX='\.(cuh?|hpp|hpp\.inc?|cpp)$'
  -FORMAT_HEADER_REGEX='^(benchmark|core|cuda|hip|include/ginkgo/core|omp|reference|dpcpp|common/unified|test)/'
  -FORMAT_REGEX='^(common|examples|test_install)/'
  +FORMAT_HEADER_REGEX='^(benchmark|core|cuda|hip|include/ginkgo/core|omp|reference|dpcpp|common/unified|test/[^t]|test/t[^e])/'
  +FORMAT_REGEX='^(common|examples|test/test_)/'
  CLANG_FORMAT=clang-format-9
  echo -n "Collecting information on triggering PR"
  