Drop Node.js v20 from default `call-test` matrix

[ybiquitous]

Background

Node.js v20 reached EOL on 2026-04-30, ref: https://nodejs.org/en/about/previous-releases

The default node-version input matrix in the call-test workflow still includes "20":

.github/.github/workflows/call-test.yml

Lines 9 to 10 in e5488b8

	# TODO: v20 is already EOL. Drop it. Ref #105
	default: '["20", "22", "24", "26"]' # https://nodejs.org/en/about/previous-releases

Proposal

Remove "20" from the default.

Considerations

We have to check for any negative impact from the removal. If a package supports Node.js v20, including it in the test matrix is reasonable.

[jeddy3]

SGTM, thank you.