Merge branch 'docs/update-sast-troubleshooting' into 'master'

Docs: add Semgrep link to sast troubleshooting

See merge request gitlab-org/gitlab!61944

doc/user/application_security/sast/index.md

@@ -772,3 +772,7 @@ For Maven builds, add the following to your `pom.xml` file:
 ### Flawfinder encoding error
 
 This occurs when Flawfinder encounters an invalid UTF-8 character. To fix this, convert all source code in your project to UTF-8 character encoding. This can be done with [`cvt2utf`](https://github.com/x1angli/cvt2utf) or [`iconv`](https://www.gnu.org/software/libiconv/documentation/libiconv-1.13/iconv.1.html) either over the entire project or per job using the [`before_script`](../../../ci/yaml/README.md#before_script) feature.
+
+### Semgrep slowness, unexpected results, or other errors
+
+If Semgrep is slow, reports too many false positives or false negatives, crashes, fails, or is otherwise broken, see the Semgrep docs for [troubleshooting GitLab SAST](https://semgrep.dev/docs/troubleshooting/gitlab-sast/).