fix(ci): drop deleted packages/core-domain/ from Dockerfile (#72)

PR #68 folded `@anchr/core-domain` into `src/domain/` and deleted the
package directory. The Dockerfile's COPY step still listed
`packages/core-domain/deno.json`, which now fails the build with
"not found":

    > [app  8/20] COPY packages/core-domain/deno.json ./packages/core-domain/:
    failed to compute cache key: ... "/packages/core-domain/deno.json": not found

Drop that line. The remaining six workspace members are still required
for `deno install` to resolve members before `COPY . .` lands the
source tree.

Verified: workspace declaration in `deno.json` lists six members
(core-runtime, core-cashu, tlsn-toolkit, photo-bounty,
cashu-frost-oracle, cashu-conditional-swap) — all still present in the
Dockerfile.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: motxx

Dockerfile

@@ -31,7 +31,6 @@ COPY --from=rust-builder /build/crates/tlsn-prover/target/release/tlsn-prove /us
 # source tree lands in the next COPY step.
 COPY deno.json deno.lock ./
 COPY packages/core-runtime/deno.json ./packages/core-runtime/
-COPY packages/core-domain/deno.json ./packages/core-domain/
 COPY packages/core-cashu/deno.json ./packages/core-cashu/
 COPY packages/tlsn-toolkit/deno.json ./packages/tlsn-toolkit/
 COPY packages/photo-bounty/deno.json ./packages/photo-bounty/