[Chapel Merge] Don't run pidigits w/ cobegin using valgrind for t

Branch: refs/heads/main
Revision: bdabc2d
Author: bradcray
Link: https://github.com/chapel-lang/chapel/pull/19189
Log Message:

Merge pull request #19189 from bradcray/pidigits-skip-cobegin-1000-for-valgrind

Don't run pidigits w/ cobegin using valgrind for the 10000 problem size

[trivial, not reviewed]

The cobegin version with fifo and valgrind is simply too slow to
be worth spending time on at the largest problem size (it takes
40 minutes), so let's skip it.

Modified Files:
M test/studies/shootout/pidigits/bradc/pidigits-blc.execopts

Compare: https://github.com/chapel-lang/chapel/compare/c977ca5e252f...bdabc2d53b5b