chore(changesets): remove stale @loop-engine/dsl from ignore list

`@changesets/config@3.1.3` validates `ignore` entries against the
current workspace and rejects the config when a referenced package
does not exist. `@loop-engine/dsl` is reserved for the D-18 rename
work in Branch D and has no corresponding workspace package today,
so every invocation of `pnpm changeset pre enter` / `pnpm changeset
version` fails at the config-read step with:

  ValidationError: The package or glob expression "@loop-engine/dsl"
  is specified in the `ignore` option but it is not found in the project.

Removing the stale entry unblocks release tooling without touching
Branch D scope. When Branch D creates `@loop-engine/dsl`, its prompt
will decide whether to re-add the ignore (i.e. whether dsl lives on
the main release cycle or a separate track) with real package context
in hand.

Zero runtime impact; tooling-config hygiene only. Logged as
F-PA7-CI-02 (observation-tier · C-15 instance · release-tooling gate
surfacing drift on first exercise).

Surface-Reconciliation-Id: SR-019 (release)

Author: betterdataco

.changeset/config.json

@@ -6,5 +6,5 @@
   "access": "public",
   "baseBranch": "main",
   "updateInternalDependencies": "patch",
-  "ignore": ["@loop-engine/dsl"]
+  "ignore": []
 }