Unignore Prague ref tests and remove osakaTime from Prague

[siladu]

PR description

No need to ignore Prague tests now (think the specific BLS ignores were all that were required)

Removing osakaTime from Prague Schedule fixes some tests when using https://github.com/ethereum/execution-spec-tests/releases/tag/pectra-devnet-5%40v1.2.0
and doesn't break main.

Fixed Issue(s)

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• Checked out our contribution guidelines?
• Considered documentation and added the doc-change-required label to this PR if updates are required.
• Considered the changelog and included an update if required.
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Locally, you can run these tests to catch failures early:

• unit tests: ./gradlew build
• acceptance tests: ./gradlew acceptanceTest
• integration tests: ./gradlew integrationTest
• reference tests: ./gradlew ethereum:referenceTests:referenceTests

[siladu]

@shemnon any issue with removing this line?

Removing osakaTime from Prague Schedule fixes some tests when using ethereum/execution-spec-tests@pectra-devnet-5%40v1.2.0 (release).

[shemnon]

This was a there when EOF tests were still in the strange prague fork. OK to remove.