Remove "sherlock" from bug report template (yarnpkg#6306)

The linked documentation doesn't exist anymore.
The associated website for the tool [1] shows some useful information,
but (IMHO) it's unclear to see how to apply it in a fresh repo.

Additionally, `arcanis` mentioned in a comment here [2] that perhaps it
should be removed since it's not often used and the playground is
broken.

Fixes yarnpkg#5837
Fixes yarnpkg#5950

[1] https://github.com/arcanis/sherlock
[2] yarnpkg#6139 (comment)


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.github/ISSUE_TEMPLATE/bug-report.yml

@@ -26,17 +26,6 @@ body:
       label: To reproduce
       description: |
         The _minimal_ information needed to reproduce your issue (ideally a package.json with a single dep). Note that bugs without minimal reproductions **will** be closed as non-actionable.
-
-        **IMPORTANT**: We **strongly** prefer reproductions that use Sherlock. Please check our documentation for more information: https://yarnpkg.com/advanced/sherlock
-      placeholder: |
-        ```js repro
-        // Sherlock reproduction. For instance:
-        await packageJsonAndInstall({
-          dependencies: {
-            [`packageName`]: `x.y.z`,
-          },
-        });
-        ```
     validations:
         required: true