[CI] Update Linux Dockerfiles (#6894)

- Install the distribution's gtest (libgtest-dev / gtest-devel) in the
  Debian, Ubuntu and Fedora images, so configuring the test suite no
  longer downloads googletest; Arch already had it.
- Drop the toolchain meta packages. g++, Ninja and cmake are all that is
  used, and make is not: Ninja is the generator on every Linux leg. The
  DEB legs keep dpkg-dev, which CPack needs for dpkg-shlibdeps when
  CPACK_DEBIAN_PACKAGE_SHLIBDEPS is on.
- Use the slim Debian bases and install Fedora packages with --nodocs.
- Define the global rng in the tests that pull the server game classes
  out of server_remote, as the other server tests already do. Debian's
  libgtest.a leaves a std::string reference undefined, so the linker
  drags server_protocolhandler.cpp and the classes behind it into any
  test that links the library, and those need the symbol.

git, ca-certificates, libcurl and OpenSSL stay: sentry-native is cloned
over git at configure time on every packaging leg, and OpenSSL also backs
CryptoUtil. mariadb-devel stays on Fedora for the same reason it is
installed elsewhere: without it Servatrice configures successfully but
silently loses its MySQL connector.

Co-authored-by: Lukas Brübach <44814898+BruebachL@users.noreply.github.com>

tests/loader_local_matching_test.cpp

@@ -23,10 +23,14 @@
 #include <libcockatrice/card/printing/exact_card.h>
 #include <libcockatrice/card/set/card_set.h>
 #include <libcockatrice/interfaces/noop_card_set_priority_controller.h>
+#include <libcockatrice/rng/rng_abstract.h>
 #include <libcockatrice/settings/paths_settings.h>
 #include <qnamespace.h>
 #include <string>
 
+// Referenced by other translation units in the server_remote library.
+RNG_Abstract *rng = nullptr;
+
 namespace
 {