internal: removes unused helper function isCVE

I guess this was attempted to be used here: https://github.com/vrnvu/vulndb/blob/b776e182e6934a1e7bcab96f018f1b26ee3f3f52/internal/ghsa/ghsa.go#L206

Change-Id: Ie9fd51079210dbb653c483b48c0dd27ac2f12165
GitHub-Last-Rev: b776e182e6934a1e7bcab96f018f1b26ee3f3f52
GitHub-Pull-Request: golang/vulndb#1116
Reviewed-on: https://go-review.googlesource.com/c/vulndb/+/452295
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: Tatiana Bradley <tatiana@golang.org>
Run-TryBot: Tatiana Bradley <tatiana@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
diff --git a/internal/ghsa/ghsa.go b/internal/ghsa/ghsa.go
index 44f3e31..2256cc7 100644
--- a/internal/ghsa/ghsa.go
+++ b/internal/ghsa/ghsa.go
@@ -240,12 +240,3 @@
 
 	return query.SA.securityAdvisory()
 }
-
-func isCVE(ids []Identifier) bool {
-	for _, id := range ids {
-		if id.Type == "CVE" {
-			return true
-		}
-	}
-	return false
-}