feat(seccomp): Add support for LoongArch64 architecture

[yzewei]

What is this change?

This pull request adds support for the LoongArch64 architecture to the default Seccomp profile.

LoongArch64 is a modern instruction set architecture developed by Loongson Technology. Adding it to the default profile is essential for ensuring containers running on LoongArch64 systems have a secure, functional default Seccomp policy.

Why is this needed?

Without this change, containers running on LoongArch64 hosts might default to an overly restrictive or non-functional Seccomp profile, potentially leading to runtime issues or requiring users to manually configure a policy. This patch ensures parity with other supported architectures like RISCV64, ARM64, etc.

How does this address the need?

The change modifies three files to incorporate LoongArch64 support:

1. seccomp/default.json: Adds SCMP_ARCH_LOONGARCH64 to the list of supported architectures in the JSON profile.
2. seccomp/default_linux.go: Adds specs.ArchLOONGARCH64 to the list of default architectures for Linux.
3. seccomp/seccomp_linux.go: Maps the Go environment's loong64 string to the appropriate specs.ArchLOONGARCH64 and maps it back to the native loongarch64 string, allowing the runtime to correctly identify and use the architecture's profile.

/cc @moby/profiles-maintainers

[yzewei]

@AkihiroSuda Thanks！