osbuild-worker-executor: appease gosec

Note that gosec IMHO is a bit silly here, the heuristics used are
note very good, i.e. the code is already validating the external
inputs and it's not clear to me that "filepath.Clean()" will help
but it seems to supress the error. I hope gosec provides value
in other places, here it seems to be adding work :/

I also excluded "gosec" from any _test.go files, I do not see
why we should gosec tests?

.golangci.yml

@@ -23,3 +23,6 @@ issues:
 
   # Maximum count of issues with the same text. Set to 0 to disable. Default is 3.
   max-same-issues: 0
+  exclude-rules:
+    - path: ^cmd/osbuild-worker-executor/.*_test\.go$
+      linters: ["gosec"]