travis: remove unused scons code path

Signed-off-by: Eric Engestrom <eric.engestrom@intel.com>

.travis.yml

@@ -58,12 +58,6 @@ install:
       pip2 install --user mako;
     fi
 
-  # Install a more modern scons from pip.
-  - if test "x$BUILD" = xscons; then
-      pip2 install --user "scons>=2.4";
-      pip2 install --user mako;
-    fi
-
   # Install dependencies where we require specific versions (or where
   # disallowed by Travis CI's package whitelisting).
 
@@ -87,10 +81,6 @@ script:
       make && eval $MAKE_CHECK_COMMAND;
     fi
 
-  - if test "x$BUILD" = xscons; then
-      scons $SCONS_TARGET && eval $SCONS_CHECK_COMMAND;
-    fi
-
   - |
     if test "x$BUILD" = xmeson; then
       if test -n "$LLVM_CONFIG"; then