Update Wycheproof ecdh_secp521r1_test.json to v1

[Sajjon]

Update Wycheproof testvector ecdh_secp521r1_test v0 to ecdh_secp521r1_test v1.

Checklist

• I've run tests to see all new and existing tests pass
• I've followed the code style of the rest of the project
• I've read the Contribution Guidelines
• I've updated the documentation if necessary

If you've made changes to gyb files

• I've run .script/generate_boilerplate_files_with_gyb and included updated generated files in a commit of this pull request

Motivation:

We ought to use as many and as up to date test vectors as possible. Wycheproofs v0 were created 4 years ago and were due some upgrade.

Modifications:

• Replaced the v0 with the v1 version.
• Changed fatalError in test code with a failable init (same change as in Update Wycheproof ecdh_secp256r1_test.json to v1 #160)

Result:

Number of tests is now 916 instead of v0's test count of 492.

[Lukasa]

@swift-server-bot test this please