support/testing/tests/toolchain/test_external_synopsys.py: drop tests

The Synopsys external toolchain has been disabled in commit
11a8cdd2bbbd0ef4adf600e4792d75f6f2122ec8, causing the test cases
testing this toolchain to fail. Let's drop those tests for now, they
can always be re-added later on.

Fixes:

  https://gitlab.com/buildroot.org/buildroot/-/jobs/8892697531
  https://gitlab.com/buildroot.org/buildroot/-/jobs/8892697528
  https://gitlab.com/buildroot.org/buildroot/-/jobs/8892697524
  https://gitlab.com/buildroot.org/buildroot/-/jobs/8892697519
  https://gitlab.com/buildroot.org/buildroot/-/jobs/8892697517
  https://gitlab.com/buildroot.org/buildroot/-/jobs/8892697516

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
[Julien: remove the DEVELOPERS entry]
Signed-off-by: Julien Olivain <ju.o@free.fr>

DEVELOPERS

@@ -3220,7 +3220,6 @@ F:	support/testing/tests/package/test_python_flask_expects_json.py
 F:	support/testing/tests/package/test_python_git.py
 F:	support/testing/tests/package/test_python_unittest_xml_reporting.py
 F:	support/testing/tests/toolchain/test_external_arm.py
-F:	support/testing/tests/toolchain/test_external_synopsys.py
 F:	toolchain/
 
 N:	Timo Ketola <timo.ketola@exertus.fi>

support/testing/tests/toolchain/test_external_synopsys.py

@@ -1,91 +0,0 @@
-from tests.toolchain.test_external import TestExternalToolchain
-
-
-class TestExternalToolchainSynopsysArc700LE(TestExternalToolchain):
-    config = """
-        BR2_arcle=y
-        BR2_arc770d=y
-        BR2_TOOLCHAIN_EXTERNAL=y
-        BR2_TOOLCHAIN_EXTERNAL_SYNOPSYS_ARC=y
-        BR2_TOOLCHAIN_EXTERNAL_SYNOPSYS_ARC700=y
-        # BR2_TARGET_ROOTFS_TAR is not set
-        """
-    toolchain_prefix = "arc-linux"
-
-    def test_run(self):
-        TestExternalToolchain.common_check(self)
-
-
-class TestExternalToolchainSynopsysArc700BE(TestExternalToolchain):
-    config = """
-        BR2_arceb=y
-        BR2_arc770d=y
-        BR2_TOOLCHAIN_EXTERNAL=y
-        BR2_TOOLCHAIN_EXTERNAL_SYNOPSYS_ARC=y
-        BR2_TOOLCHAIN_EXTERNAL_SYNOPSYS_ARC700=y
-        # BR2_TARGET_ROOTFS_TAR is not set
-        """
-    toolchain_prefix = "arceb-linux"
-
-    def test_run(self):
-        TestExternalToolchain.common_check(self)
-
-
-class TestExternalToolchainSynopsysArcHSGlibcLE(TestExternalToolchain):
-    config = """
-        BR2_arcle=y
-        BR2_archs38_full=y
-        BR2_TOOLCHAIN_EXTERNAL=y
-        BR2_TOOLCHAIN_EXTERNAL_SYNOPSYS_ARC=y
-        BR2_TOOLCHAIN_EXTERNAL_SYNOPSYS_ARCHS_GLIBC=y
-        # BR2_TARGET_ROOTFS_TAR is not set
-        """
-    toolchain_prefix = "arc-linux"
-
-    def test_run(self):
-        TestExternalToolchain.common_check(self)
-
-
-class TestExternalToolchainSynopsysArcHSGlibcBE(TestExternalToolchain):
-    config = """
-        BR2_arceb=y
-        BR2_archs38_full=y
-        BR2_TOOLCHAIN_EXTERNAL=y
-        BR2_TOOLCHAIN_EXTERNAL_SYNOPSYS_ARC=y
-        BR2_TOOLCHAIN_EXTERNAL_SYNOPSYS_ARCHS_GLIBC=y
-        # BR2_TARGET_ROOTFS_TAR is not set
-        """
-    toolchain_prefix = "arceb-linux"
-
-    def test_run(self):
-        TestExternalToolchain.common_check(self)
-
-
-class TestExternalToolchainSynopsysArcHSuClibcLE(TestExternalToolchain):
-    config = """
-        BR2_arcle=y
-        BR2_archs38_full=y
-        BR2_TOOLCHAIN_EXTERNAL=y
-        BR2_TOOLCHAIN_EXTERNAL_SYNOPSYS_ARC=y
-        BR2_TOOLCHAIN_EXTERNAL_SYNOPSYS_ARCHS_UCLIBC=y
-        # BR2_TARGET_ROOTFS_TAR is not set
-        """
-    toolchain_prefix = "arc-linux"
-
-    def test_run(self):
-        TestExternalToolchain.common_check(self)
-
-
-class TestExternalToolchainSynopsysArcHSuClibcBE(TestExternalToolchain):
-    config = """
-        BR2_arceb=y
-        BR2_archs38_full=y
-        BR2_TOOLCHAIN_EXTERNAL=y
-        BR2_TOOLCHAIN_EXTERNAL_SYNOPSYS_ARC=y
-        BR2_TOOLCHAIN_EXTERNAL_SYNOPSYS_ARCHS_UCLIBC=y
-        # BR2_TARGET_ROOTFS_TAR is not set
-        """
-    toolchain_prefix = "arceb-linux"
-
-    def test_run(self):
-        TestExternalToolchain.common_check(self)