add gosec (3rd sast tool)

sast_results/gosec.txt

@@ -0,0 +1,17 @@
+Results:
+
+
+[/home/vovuas/linux-auth/internal/config/config.go:41] - G304 (CWE-22): Potential file inclusion via variable (Confidence: HIGH, Severity: MEDIUM)
+    40: func Load(path string) (*Config, error) {
+  > 41: 	data, err := os.ReadFile(path)
+    42: 	if err != nil {
+
+Autofix: Consider using os.Root to scope file access under a fixed root (Go >=1.24). Prefer root.Open/root.Stat over os.Open/os.Stat to prevent directory traversal.
+
+Summary:
+  Gosec  : 2.24.7
+  Files  : 8
+  Lines  : 545
+  Nosec  : 0
+  Issues : 1
+