Fix L3 DA config when L2 AnyTrust is enabled

[douglance]

Summary

• isolate data availability config generation in scripts/config.ts
• keep the L2 AnyTrust config on the parent chain path
• explicitly reset the built-in L3 node data availability config to non-AnyTrust

Verification

• bash -n test-node.bash
• git diff --check
• attempted runtime validation, but the local environment was blocked by existing services already bound to the standard Nitro testnode ports

[joshuacolvin0]

LGTM