ci: add gcc-11/12 and clang-13/15 to test-deps for multi-compiler

multi-compiler matrix asks for gcc-11, gcc-12, clang-13, clang-14,
clang-15 as explicit binary names. The image only had unversioned
'gcc' (= gcc-12) and 'clang' (= clang-14), so make hit 'gcc-11: not
found' for any other matrix entry (run 26538567521 job 78173898262).

Author: aidangarske

docker/wolfprovider-test-deps/Dockerfile

@@ -16,10 +16,12 @@ RUN apt-get update \
     && apt-get install -y --no-install-recommends \
         # core build toolchain
         build-essential gcc g++ make m4 gettext \
+        gcc-11 g++-11 gcc-12 g++-12 \
         autoconf automake autoconf-archive autopoint autotools-dev \
         libtool libtool-bin pkg-config pkgconf \
         cmake meson ninja-build bison flex gperf gengetopt help2man \
         clang clang-tools cppcheck libc++-dev \
+        clang-13 clang-15 \
         # vcs, transport, compression, scripting
         git git-all curl wget ca-certificates patch xxd dpkg-dev jq \
         gawk perl python3 python3-pip python3-venv python3-wheel \