bazel: is_dev_linux config setting should be false when cross_flag is

true

When cross-compiling on a gce worker and invoking bazel directly, build
fails with "cannot find -lresolv_wrapper", owing to the fact that
is_dev_linux is not mutually exclusive of cross_linux. That is, when
both configs are active "-lresolv_wrapper" is passed to clinkopts in
pkg/ccl/gssapiccl/BUILD.bazel; the cross-compiler doesn't have this lib nor
does it need it.

Note, when using ./dev instead of bazel, the above issue is side-stepped
because the dev wrapper invokes bazel inside docker which ignores
~/.bazelrc.

The workaround is to make is_dev_linux false when cross_flag is true.

Epic: none

Release note: None

build/toolchains/BUILD.bazel

@@ -346,6 +346,7 @@ config_setting(
     ],
     flag_values = {
         ":dev_flag": "true",
+        ":cross_flag": "false",
     },
 )