Lower the Python floor to 3.10, release 0.1.1

[remislp]

The >=3.11 came from the initial commit and was never earned: dcio uses
no 3.11 syntax and no 3.11 stdlib — no tomllib, no typing.Self, no
exception groups, no match statements, nothing.

It became a real constraint when SCALCS took dcio as a dependency
(DCPROGS/SCALCS#18). SCALCS supports 3.10, so pip could not resolve the
requirement there at all:

ERROR: Could not find a version that satisfies the requirement dcio>=0.1.0
ERROR: No matching distribution found for dcio>=0.1.0

The alternatives were to drop 3.10 from SCALCS to satisfy a floor that is not
required, or to keep two copies of burst segmentation in the stack. Neither is
worth it.

Proven, not asserted

CI now covers 3.10 through 3.13, and the oldest-deps job pins 3.10 as
well — so the floor is a tested fact, for the same reason that job already
exists for the numpy minimum.

345 passing.

EKDIST's >=3.11 was inherited from this one and can come down too, in its
own change.

Merge and I will tag v0.1.1.

🤖 Generated with Claude Code