[ja|pt] Drop temporary link-checking rules

[chalin]

• Refactor java instrumentation #5276 required that we disable link checking for some ja and pt pages
• This issue is a reminder to drop the temporary rule in https://github.com/open-telemetry/opentelemetry.io/blob/main/.htmltest.yml after the ja and pt pages are updated

Tasks

• ja page patch - [ja] Temporarily patch page to avoid link-check failure #5609
• pt page patch - [pt] Temporarily patch page to avoid link-check failure #5603

/cc
@open-telemetry/docs-pt-approvers
@open-telemetry/docs-ja-approvers

[chalin]

@open-telemetry/docs-ja-approvers can you submit a PR similar to what the pt team did?

[katzchang]

@chalin Thank you for your heads-up, I'll take a look!