ci: Increase toolchain build timeout to 12 hours

This commit increases the CI workflow toolchain build job timeout to 12
hours because the default value of 6 hours is insufficient for the
toolchains with many multi-lib variants (e.g. ARM And RISC-V).

Signed-off-by: Stephanos Ioannidis <[email protected]>

Author: stephanosio

.github/workflows/ci.yml

@@ -426,6 +426,7 @@ jobs:
     runs-on:
       group: ${{ matrix.host.runner }}
     container: ${{ matrix.host.container }}
+    timeout-minutes: 720 
 
     defaults:
       run: