feat: remove CXX flags from make call for Callas binaries (thx @romeyke)

tasks/compile_callas_binaries.yml

@@ -65,5 +65,5 @@
 # inline. Molecule errors are turned off for this.
 - name: compile PDF/A-Webservice binary    # noqa command-instead-of-shell
   ansible.builtin.shell:
-    cmd: 'CXXFLAGS="-std=c++11" make --directory /opt/pdfa_webservice/src/'
+    cmd: 'make --directory /opt/pdfa_webservice/src/'
   changed_when: false    # This always changes, because the dest path is fresh.