`metadata.tools` not merged correctly when one SBOM uses legacy format and the other uses the newer format

I have 2 SBOM files. One created with `cyclonedx-maven-plugin`
```json
{
"bomFormat" : "CycloneDX",
"specVersion" : "1.6",
"metadata" : {
"tools" : {
"components" : [
{
"type" : "library",
"author" : "OWASP Foundation",
"group" : "org.cyclonedx",
"name" : "cyclonedx-maven-plugin",
"version" : "2.9.0",
"description" : "CycloneDX Maven plugin",
"hashes" : [
{
"alg" : "MD5",
"content" : "dfaeab7ec837ce07874e2ee66fdc57d3"
},
{
"alg" : "SHA-1",
"content" : "8bab47bafc8183d0a5f37790ff55ed05ead1ae2d"
},
{
"alg" : "SHA-256",
"content" : "67117e03eae4a03ca8bab3add044995f4899aa21798a2510b8265ef8101e90ac"
},
{
"alg" : "SHA-512",
"content" : "ae6b706516bb76da806b7854aef9e348fa593f5159ae9d693ad38942165c0ebc0846d977a477f6029612d43468fd2cd73a5aa253c228a94fb8d184e0acefc3d2"
},
{
"alg" : "SHA-384",
"content" : "ee872354d8b0dcd6f9835a913b3aaba70d9365a46043be78020183282a1e9fca812e969246cbe31d642541591b46648b"
},
{
"alg" : "SHA3-384",
"content" : "e5167f9e7ceba3b7b4d1900c404543907868745334bedc69cdf79c271727148413033a3b1426b733b7549e612e44adee"
},
{
"alg" : "SHA3-256",
"content" : "41fc0bc2275f354e2c7da01041ce73ce677364799cba53920a180aa5d4571c63"
},
{
"alg" : "SHA3-512",
"content" : "ed7f97900b09b818dbc0b8a23c00a2843e1bc34e2e8eb5b6df52533af0a15b721de6f7d5c2fd9352b8d4fde768e080053b40a16f0f9f04c336fe9b44abe83fc0"
}
]
}
]
}
}
}
```

and one created with `@cyclonedx/cyclonedx-npm`
```json
{
"$schema": "http://cyclonedx.org/schema/bom-1.6.schema.json",
"bomFormat": "CycloneDX",
"specVersion": "1.6",
"metadata": {
"tools": [
{
"name": "npm",
"version": "10.8.2"
},
{
"vendor": "@cyclonedx",
"name": "cyclonedx-npm",
"version": "1.19.3",
"externalReferences": [
{
"url": "git+https://github.com/CycloneDX/cyclonedx-node-npm.git",
"type": "vcs",
"comment": "as detected from PackageJson property \"repository.url\""
},
{
"url": "https://github.com/CycloneDX/cyclonedx-node-npm#readme",
"type": "website",
"comment": "as detected from PackageJson property \"homepage\""
},
{
"url": "https://github.com/CycloneDX/cyclonedx-node-npm/issues",
"type": "issue-tracker",
"comment": "as detected from PackageJson property \"bugs.url\""
}
]
},
{
"vendor": "@cyclonedx",
"name": "cyclonedx-library",
"version": "6.11.0",
"externalReferences": [
{
"url": "git+https://github.com/CycloneDX/cyclonedx-javascript-library.git",
"type": "vcs",
"comment": "as detected from PackageJson property \"repository.url\""
},
{
"url": "https://github.com/CycloneDX/cyclonedx-javascript-library#readme",
"type": "website",
"comment": "as detected from PackageJson property \"homepage\""
},
{
"url": "https://github.com/CycloneDX/cyclonedx-javascript-library/issues",
"type": "issue-tracker",
"comment": "as detected from PackageJson property \"bugs.url\""
}
]
}
]
}
}
```
(I removed irrelevant parts for readability).

`cyclonedx-maven-plugin` creates an SBOM that uses the newer format for the `metadata.tools` field, `@cyclonedx/cyclonedx-npm` creates one that uses the legacy format.

If I try to merge these two SBOMs, only the tools in the legacy format are included in the result:
```bash
cyclonedx-cli merge --input-files maven-sbom.json npm-sbom.json --output-format json > merged-sbom.json
```
```json
{
"bomFormat": "CycloneDX",
"specVersion": "1.6",
"metadata": {
"tools": [
{
"name": "npm",
"version": "10.8.2"
},
{
"vendor": "@cyclonedx",
"name": "cyclonedx-npm",
"version": "1.19.3",
"externalReferences": [
{
"url": "git\u002Bhttps://github.com/CycloneDX/cyclonedx-node-npm.git",
"type": "vcs",
"comment": "as detected from PackageJson property \u0022repository.url\u0022"
},
{
"url": "https://github.com/CycloneDX/cyclonedx-node-npm#readme",
"type": "website",
"comment": "as detected from PackageJson property \u0022homepage\u0022"
},
{
"url": "https://github.com/CycloneDX/cyclonedx-node-npm/issues",
"type": "issue-tracker",
"comment": "as detected from PackageJson property \u0022bugs.url\u0022"
}
]
},
{
"vendor": "@cyclonedx",
"name": "cyclonedx-library",
"version": "6.11.0",
"externalReferences": [
{
"url": "git\u002Bhttps://github.com/CycloneDX/cyclonedx-javascript-library.git",
"type": "vcs",
"comment": "as detected from PackageJson property \u0022repository.url\u0022"
},
{
"url": "https://github.com/CycloneDX/cyclonedx-javascript-library#readme",
"type": "website",
"comment": "as detected from PackageJson property \u0022homepage\u0022"
},
{
"url": "https://github.com/CycloneDX/cyclonedx-javascript-library/issues",
"type": "issue-tracker",
"comment": "as detected from PackageJson property \u0022bugs.url\u0022"
}
]
}
]
}
}
```

The order of the input files did not matter