Fix Lock "compiler speclet" URL

[richardszalay]

Summary

The "compiler speclet" URL in the System.Threading.Lock class documentation was missing the language version folder under proposals/.

[richardszalay]

Question: This PR is a like-for-like / as-is fix, but would it be better to link to the published document page rather than the GitHub URL? Let me know and I can update this PR accordingly

[learn-build-service-prod]

Learn Build status updates of commit 6ddbbc5:

✅ Validation status: passed

File	Status	Preview URL	Details
xml/System.Threading/Lock.xml	✅Succeeded	View

For more details, please refer to the build report.

For any questions, please:

• Try searching the learn.microsoft.com contributor guides
• Post your question in the Learn support channel

[kouvel]

Question: This PR is a like-for-like / as-is fix, but would it be better to link to the published document page rather than the GitHub URL? Let me know and I can update this PR accordingly

Thanks for fixing this! Yea that published link seems like a better one to put there, the above looks good to me.

[richardszalay]

Great I'll update the PR with the published link.

[learn-build-service-prod]

Learn Build status updates of commit 0aac76e:

✅ Validation status: passed

File	Status	Preview URL	Details
xml/System.Threading/Lock.xml	✅Succeeded	View

For more details, please refer to the build report.

For any questions, please:

• Try searching the learn.microsoft.com contributor guides
• Post your question in the Learn support channel

[kouvel]

LGTM, thanks!