refactor: remove need in ruby code to have`type` declared in jsonschema that contains a `const`

[kbroch-rivosinc]

metasource jsonschema tool found following anti-pattern:

❯ jsonschema lint --ignore schemas/json-schema-draft-07.json schemas/.
/Users/kbroch/rvi/non-repo-repos/riscv-unified-db/schemas/manual_schema.json:
  Setting `type` alongside `const` is considered an anti-pattern, as the constant already implies its respective type (const_with_type)
    at schema location "/properties/$schema"
/Users/kbroch/rvi/non-repo-repos/riscv-unified-db/schemas/manual_schema.json:
  Setting `type` alongside `const` is considered an anti-pattern, as the constant already implies its respective type (const_with_type)
    at schema location "/properties/kind"
/Users/kbroch/rvi/non-repo-repos/riscv-unified-db/schemas/manual_version_schema.json:
  Setting `type` alongside `const` is considered an anti-pattern, as the constant already implies its respective type (const_with_type)
    at schema location "/properties/$schema"
/Users/kbroch/rvi/non-repo-repos/riscv-unified-db/schemas/manual_version_schema.json:
  Setting `type` alongside `const` is considered an anti-pattern, as the constant already implies its respective type (const_with_type)
    at schema location "/properties/kind"
error: Could not resolve the requested schema
  at tag:schema_defs.json

@dhower-qc said: #401 (comment)

We should be able to refactor code to derive "type = string" from the const and remove this anti-pattern from the schema files.

[kbroch-rivosinc]

closing as this landed #667