CI build failure on Linux

All distributions:

CMake Error at /usr/share/cmake/Modules/FindPackageHandleStandardArgs.cmake:233 (message):
  Could NOT find GTest (missing: GTEST_LIBRARY GTEST_INCLUDE_DIR
  GTEST_MAIN_LIBRARY)
Call Stack (most recent call first):
  /usr/share/cmake/Modules/FindPackageHandleStandardArgs.cmake:603 (_FPHSA_FAILURE_MESSAGE)
  /usr/share/cmake/Modules/FindGTest.cmake:273 (FIND_PACKAGE_HANDLE_STANDARD_ARGS)
  tests/CMakeLists.txt:40 (find_package)

rpm-based distributions:

error: Installed (but unpackaged) file(s) found:
   /usr/lib64/libjami-core.a