fix(archive): files dst is never passed through the template engine - #7118

Whether a bad dst template fails the release depends on what is on disk.

This block sits below the len(files) == 0 / continue at lines 35-41, so the template is only applied when the glob matched something. src is templated at line 23, before fileglob.Glob, so it always fails.

Trigger:

archives:
  - files:
      - src: "docs/*"
        dst: "docs_{{ .Env.NOPE }}"

With docs/ empty, the release succeeds and logs no files matched. Add one file to docs/ and the same config now aborts the release. Same config, two outcomes, decided by the working tree — so a typo can sit dormant in a repo for months and then break a release, or fail on one platform and pass on another when the glob is platform-dependent.

That is the exact src/dst asymmetry this PR sets out to remove, so it seems worth closing here rather than leaving a second one behind. The description argues the placement protects against "aborting the release on a bad template", but the len(files) == 0 skip exists to tolerate globs that match nothing (see #4013, which made it warn only for non-default globs) — not to tolerate malformed config. A malformed template is a config error and should be reported deterministically.

Smallest fix — move the apply up next to the src one, which also collapses it into the existing call:

glob, err := template.Apply(f.Source)
if err != nil {
	return result, fmt.Errorf("failed to apply template %s: %w", f.Source, err)
}
if err := template.ApplyAll(&f.Destination); err != nil {
	return result, err
}

That also matches internal/pipe/nfpm/nfpm.go, which does ApplyAll(&content.Source, &content.Destination, ...) in one go — the precedent cited in the description. Note the current error text also duplicates the template string, since tmpl errors already include it; ApplyAll avoids that too.

Needed test: a subtest with a glob that matches nothing and a bad dst template, asserting the error — e.g. src: "./testdata/nope/**/*", dst: "var/{{ .Env.NOPE }}/", testlib.RequireTemplateError. Nothing currently pins this behaviour in either direction; rlcp no results at archivefiles_test.go:198 uses a literal dst.

This annotation is redundant, and it is the only one of three pages that gets it.

Line 117 already carries # Templates: allowed. directly above files:, which covers every entry in the list including this one. The two sibling pages documenting the same dst through the same archivefiles.Eval — package/source.md:35 and package/makeself.md:129 — use exactly that key-level annotation and have no per-entry one.

So after this hunk, archives.md annotates the same fact twice while the other two pages that gained the same capability say nothing extra, which reads as though dst templating is archives-only. It isn't: source.files[].dst and makeself.files[].dst both route through Eval (sourcearchive/source.go:106, makeself/makeself.go:257).

Smallest fix: drop the hunk. The existing line 117 is already true and now more completely so.

If the intent is to call out dst specifically, this file's own convention is field-level — see owner: at lines 138-139 — so it should sit directly above dst: and be added to all three pages, not above the list item in one of them.