Stabilize release ARM64 QEMU validation

[shrec]

What

• Fixed the release workflow ARM64 lane so it no longer runs the full ctest matrix under QEMU.
• Switched build-linux-arm64 to the same smoke-style validation already used by CI: run_selftest smoke plus test_bip324_standalone.
• Disabled Java JNI in the cross-release ARM64 configure path to keep that lane focused on native release artifacts only.

Numbers

• Previous behavior: Release / build-linux-arm64 spent ~100 minutes inside QEMU and then died on a cascade of test timeouts.
• New behavior: the job now validates ARM64 release artifacts with two targeted smoke binaries instead of the full 158-test suite under emulation.

How to get it

• Branch: dev
• Commit: d2cb1364