[lit] Reduce value of synthesized timeouts

Large timeout values (one year, positive infinity) trip up Python on
Windows with "OverflowError: timeout value is too large".  One week
seems to work and is still large enough in practice.

Thanks to Simon Pilgrim for helping me test this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@375264 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed