adding exact file name for xml-schemas referencing

[himorin]

potential fix for various errors

1. GHAction timeout mentioned at PR preview seems to be broken #635 (comment) , and fetch error on another run https://github.com/w3c/imsc/actions/runs/21958936378/job/63430777809#logs
2. file missing error for streamlined publication https://www.w3.org/TR/2026/CRD-ttml-imsc1.3-20260210/xml-schemas/

[himorin]

hrm,,, fetch error not fixed. although, copy operation error fixed (since no dir to dir copy trial does happen with this change).

[himorin]

For Failed to fetch warning, origin is
https://github.com/w3c/spec-prod/blob/ab328333cd7b56dbc1bbe726bb72caa1ac3ebf79/src/build.ts#L191
which output warning for resources that content-type (via http local server) is not text/html. List is originally built at
https://github.com/w3c/spec-prod/blob/ab328333cd7b56dbc1bbe726bb72caa1ac3ebf79/src/build.ts#L207
following listing all linked resources within source, with filtering as resource type of link, which is labelled at npm/subresources and all HTMLAnchorElement are marked as link.
https://github.com/sidvishnoi/subresources/blob/7ba165401b3c0452a53a1c5c1e6e5749eaaf2062/index.ts#L267

so, we should just ignore.

[himorin]

I believe some part of error or failure of operation will be fixed with this.

[nigelmegitt]

The GHA succeeded so this seems to be good.

[himorin]

The GHA succeeded so this seems to be good.

thank you for checking. then, let me try.
I believe I could ignore usual 2w window, since this is just tooling but not spec text (even non-normative), so let me merge now.

[himorin]

@nigelmegitt streamlined publication passed.
https://labs.w3.org/echidna/api/status?id=69ffba6d-196a-41a8-96c9-2f9361295535

so, let us see for prpreview...