[CI] Add soversion=On to Alma10 clang ninja.

As demonstrated by #21375, we
need to test building with soversion.

Author: hageboeck

.github/workflows/root-ci-config/buildconfig/alma10-clang_ninja.txt

@@ -6,4 +6,5 @@ builtin_zlib=ON
 builtin_zstd=ON
 pythia8=ON
 r=OFF
+soversion=ON
 tmva-sofie=ON