fix: handle null xray scan results with try() function

Adds proper null handling for cases where xray scan results are null,
which was causing Terraform validation failures. Uses try() function
to gracefully handle null values and provide default vulnerability counts.

Author: blink-so[bot]

registry/coder/modules/jfrog-xray/main.tf

@@ -82,13 +82,21 @@ data "xray_artifacts_scan" "image_scan" {
 
 # Extract vulnerability counts
 locals {
-  vulnerabilities = length(data.xray_artifacts_scan.image_scan.results) > 0 ? data.xray_artifacts_scan.image_scan.results[0].sec_issues : {
-    critical = 0
-    high     = 0
-    medium   = 0
-    low      = 0
-  }
-
+  vulnerabilities = try(
+    length(data.xray_artifacts_scan.image_scan.results) > 0 ? data.xray_artifacts_scan.image_scan.results[0].sec_issues : {
+      critical = 0
+      high     = 0
+      medium   = 0
+      low      = 0
+    },
+    {
+      critical = 0
+      high     = 0
+      medium   = 0
+      low      = 0
+    }
+  )
+  
   total_vulnerabilities = local.vulnerabilities.critical + local.vulnerabilities.high + local.vulnerabilities.medium + local.vulnerabilities.low
 }