patch 8.2.3302: Coverity is not run from github

Problem:    Coverity is not run from github.
Solution:   Add a coverity script. (James McCoy, closes #8714)
diff --git a/Filelist b/Filelist
index 8ff2feb..34285eb 100644
--- a/Filelist
+++ b/Filelist
@@ -9,6 +9,7 @@
 		.github/CODEOWNERS \
 		.github/workflows/ci.yml \
 		.github/workflows/codeql-analysis.yml \
+		.github/workflows/coverity.yml \
 		.gitignore \
 		.hgignore \
 		.lgtm.yml \