chore(tests): name integration test packages correctly to let them run (#10242)

# Which Problems Are Solved

After changing some internal logic, which should have failed the
integration test, but didn't, I noticed that some integration tests were
never executed. The make command lists all `integration_test` packages,
but some are named `integration`

# How the Problems Are Solved

Correct wrong integration test package names.

# Additional Changes

None

# Additional Context

- noticed internally
- backport to 3.x and 2.x

internal/api/grpc/saml/v2/integration_test/server_test.go

@@ -0,0 +1,34 @@
+//go:build integration
+
+package saml_test
+
+import (
+	"context"
+	"os"
+	"testing"
+	"time"
+
+	"github.com/zitadel/zitadel/internal/integration"
+	saml_pb "github.com/zitadel/zitadel/pkg/grpc/saml/v2"
+)
+
+var (
+	CTX      context.Context
+	IAMCTX   context.Context
+	Instance *integration.Instance
+	Client   saml_pb.SAMLServiceClient
+)
+
+func TestMain(m *testing.M) {
+	os.Exit(func() int {
+		ctx, cancel := context.WithTimeout(context.Background(), 15*time.Minute)
+		defer cancel()
+
+		Instance = integration.NewInstance(ctx)
+		Client = Instance.Client.SAMLv2
+
+		IAMCTX = Instance.WithAuthorization(ctx, integration.UserTypeIAMOwner)
+		CTX = Instance.WithAuthorization(ctx, integration.UserTypeOrgOwner)
+		return m.Run()
+	}())
+}