Bug: strptime does not handle non-zero-padded values

[johnkerl]

    Hi, I'm running into an issue when attempting to parse non zero-padded values with `strptime`:

echo d='1/6/2022' | mlr --opprint put '$ts = strptime($d,"%m/%d/%Y")'

Output

d        ts
1/6/2022 (error)

Support for non zero-padded values with the standard strptime format strings appears to be platform-specific, but I cannot find any details on whether they are supported in Go or Miller.

If non zero-padded values are not supported in Miller's strptime implementation, is there a different approach for handling such date formats?

Thanks.

Originally posted by @archetyped in #1197

[johnkerl]

Duplicate of #1355 1355