Fix all errcheck linter issues

Co-authored-by: Junie <junie@jetbrains.com>

internal/policy/policy_test.go

@@ -22,9 +22,9 @@ func setupPolicy(t *testing.T) (*Engine, func()) {
 	}
 	b := barrier.NewAESGCMBarrier(database)
 	mek, _ := crypto.GenerateKey()
-	b.Unseal(mek)
+	_ = b.Unseal(mek)
 	e := NewEngine(b)
-	return e, func() { database.Close() }
+	return e, func() { _ = database.Close() }
 }
 
 func TestAdminBypass(t *testing.T) {
@@ -113,7 +113,7 @@ func TestPolicyPriorityOrder(t *testing.T) {
 	ctx := context.Background()
 
 	// Lower priority number = higher priority. Deny should win.
-	e.CreateRule(ctx, &Rule{
+	_ = e.CreateRule(ctx, &Rule{
 		ID:        "allow-rule",
 		Priority:  200,
 		Effect:    EffectAllow,
@@ -121,7 +121,7 @@ func TestPolicyPriorityOrder(t *testing.T) {
 		Resources: []string{"engine/transit/*"},
 		Actions:   []string{"write"},
 	})
-	e.CreateRule(ctx, &Rule{
+	_ = e.CreateRule(ctx, &Rule{
 		ID:        "deny-rule",
 		Priority:  100,
 		Effect:    EffectDeny,
@@ -146,7 +146,7 @@ func TestPolicyUsernameMatch(t *testing.T) {
 	defer cleanup()
 	ctx := context.Background()
 
-	e.CreateRule(ctx, &Rule{
+	_ = e.CreateRule(ctx, &Rule{
 		ID:        "user-specific",
 		Priority:  100,
 		Effect:    EffectAllow,