Azure/GitLab: Switch over to using LLVM-10

At this point LLVM-7 is rather old.  Switch over to LLVM-10 to enable
some amount of CI coverage with newer compilers.

Signed-off-by: Tom Rini <trini@konsulko.com>

.azure-pipelines.yml

@@ -161,7 +161,7 @@ jobs:
           TEST_PY_BD: "sandbox"
         sandbox_clang:
           TEST_PY_BD: "sandbox"
-          OVERRIDE: "-O clang-7"
+          OVERRIDE: "-O clang-10"
         sandbox_spl:
           TEST_PY_BD: "sandbox_spl"
           TEST_PY_TEST_SPEC: "test_ofplatdata or test_handoff"

.gitlab-ci.yml

@@ -181,7 +181,7 @@ sandbox with clang test.py:
   tags: [ 'all' ]
   variables:
     TEST_PY_BD: "sandbox"
-    OVERRIDE: "-O clang-7"
+    OVERRIDE: "-O clang-10"
   <<: *buildman_and_testpy_dfn
 
 sandbox_spl test.py: