ci: Use --show-fail-log option

Otherwise, it's difficult to debug the failures.

Signed-off-by: Michal Rostecki <[email protected]>

.github/workflows/crossdev.yml

@@ -42,7 +42,7 @@ jobs:
 
             # Create cross environment
             eselect repository create crossdev
-            crossdev ${{ matrix.args }} --target ${{ matrix.target }}
+            crossdev ${{ matrix.args }} --show-fail-log --target ${{ matrix.target }}
 
             # zstd and its dependencies need both C and C++ toolchain. If any of them
             # is broken, the installation will fail.