Merge 'Build logs' into 'Build' in '.github/workflows/ccpp.yml:jobs.build-and-check'

This avoids the supposed issue that in case that 'make' fails, the whole
'jobs.build-and-check' stops, and 'Build logs' isn't executed, and thus there's
no indication in the GitHub UI why 'make' failed.

Using a shell pipeline is OK; the exit code of 'make' isn't lost, as per
<https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idstepsshell>,
'bash' is being run with '-o pipefail'.

.github/workflows/ccpp.yml

@@ -48,13 +48,11 @@ jobs:
                --enable-multilib
 
     - name: Build
+      shell: bash
       run: |
            cd gccrs-build; \
-           make -j $(nproc) > log 2>&1
+           make -j $(nproc) 2>&1 | tee log
            
-    - name: Build logs
-      run: cat gccrs-build/log
-
     - name: Check for new warnings
       run: |
            grep 'warning:' gccrs-build/log | sort > log_warnings;