Switch Linux toolchain to GCC 14

This change removes the usage of the GCC 12 (from devtoolset) to stay
in line with the main DuckDB that made this switch in duckdb/duckdb#20170.

Author: staticlibs

.github/composite-actions/linux-build-docker/action.yml

@@ -25,9 +25,7 @@ runs:
           cat /etc/os-release
           dnf install -y             \
             ccache                   \
-            gcc-toolset-12-gcc-c++   \
             java-1.8.0-openjdk-devel \
             ninja-build
-          source /opt/rh/gcc-toolset-12/enable
           make -C /duckdb release
         "