[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>

.ci/Ubuntu24.04/Dockerfile

@@ -2,15 +2,16 @@ FROM ubuntu:24.04
 
 RUN apt-get update && \
     DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \
-        build-essential \
         ca-certificates \
         ccache \
         cmake \
+        dpkg-dev \
         file \
         g++ \
         git \
         libcurl4-openssl-dev \
         libgl-dev \
+        libgtest-dev \
         liblzma-dev \
         libmariadb-dev-compat \
         libprotobuf-dev \