Set rangeStrategy=widen #5

From discussion on ni/python-actions#45 (comment)

We should look into using rangeStrategy=widen to update deps like pytest = ">=7.0,<8.0" to pytest = ">=7.0,<9.0".

According to @mshafer-NI the behavior with node-style ^ dependencies is to update pytest = "^7.0.0" to pytest = "^7.0.0,^8.0.0", which is a bit verbose. I expect that moving to PEP 621 dependencies will avoid this because they don't support the node-style ^ syntax.