scons: Eliminate the redundant "--colors" scons command line option.
scons: Eliminate the redundant "--colors" scons command line option.

The default behavior already is to add color to the output. The option
had an action of 'store_true' which would normally set the default value
to False, but the --no-colors option immediately after it had the action
'store_false' which apparently set the common dest 'use_colors' to True
by default. The net effect was that the --colors option did nothing.

Change-Id: I6d6473f85921f90bb629ecb32a0f0f81c02d7914
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/40875
Tested-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>
Reviewed-by: Bobby R. Bruce <b9dba908ffb6c6d8ffe449cc88b3709c13c485c2@ucdavis.edu>
Maintainer: Bobby R. Bruce <b9dba908ffb6c6d8ffe449cc88b3709c13c485c2@ucdavis.edu>

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