Fix numeric formats error messages to be inclusive

[Abdalrhman-Almarakeby]

Fixes the error messages for Zod numeric formats so that they correctly show that values are allowed to equal the minimum and maximum bounds.

This issue affected: z.int(), z.float32(), z.float64(), z.int32(), z.uint32(), z.int64(), and z.uint64() (all of the numeric formats). This PR updates their error messages.

Previously:

z.int32().safeParse(2147483648)
// Error message: "Too big: expected number to be <2147483647"

Now:

z.int32().safeParse(2147483648)
// Error message: "Too big: expected number to be <=2147483647"

Which is correct because 2147483647 parses successfully.

Same for "Too small" errors and all other numeric formats.

Also updates the docs to clarify that minimum and maximum bounds are inclusive.

Fixes #5436.