macOS GitHub CI: brew is being very flaky; stop trying to use it.

.github/actions/config-cc/action.yml

@@ -7,14 +7,17 @@ runs:
       shell: bash
       run: |
         if [ "`uname`" = "Darwin" ]; then
-          brew update
-          brew install ccache
+          # Jun 28 2023: Stopped using brew to install ccache, it
+          # was being very flaky; took ccache out of the CC/CXX/etc
+          # lines.
+          # brew update
+          # brew install ccache
           echo CFLAGS=$CFLAGS -Wno-parentheses-equality -Wno-constant-logical-operand -stdlib=libc++ >> $GITHUB_ENV
           echo CXXFLAGS=$CXXFLAGS -Wno-parentheses-equality -Wno-constant-logical-operand -stdlib=libc++ >> $GITHUB_ENV
-          echo CC=ccache /usr/bin/clang >> $GITHUB_ENV
-          echo CXX=ccache /usr/bin/clang++ >> $GITHUB_ENV
-          echo LDCXXSHARED=ccache /usr/bin/clang -bundle -undefined dynamic_lookup >> $GITHUB_ENV
-          echo LDSHARED=ccache /usr/bin/clang -bundle -undefined dynamic_lookup >> $GITHUB_ENV
+          echo CC=/usr/bin/clang >> $GITHUB_ENV
+          echo CXX=/usr/bin/clang++ >> $GITHUB_ENV
+          echo LDCXXSHARED=/usr/bin/clang -bundle -undefined dynamic_lookup >> $GITHUB_ENV
+          echo LDSHARED=/usr/bin/clang -bundle -undefined dynamic_lookup >> $GITHUB_ENV
         else
           sudo apt-get install -y ccache libmemcached-dev
           echo CFLAGS=$CFLAGS -std=gnu++11 >> $GITHUB_ENV