docs: Remove gocheck related section

Signed-off-by: Tam Mach <tam.mach@cilium.io>

.golangci.yaml

@@ -70,7 +70,7 @@ linters-settings:
             recommendations:
               - testing
               - github.com/stretchr/testify/assert
-            reason: "gocheck has been deprecated, see https://docs.cilium.io/en/latest/contributing/testing/unit/#migrating-tests-off-of-gopkg-in-check-v1"
+            reason: "gocheck has been deprecated, see https://github.com/cilium/cilium/issues/28596"
         - go.uber.org/multierr:
             recommendations:
               - errors

Documentation/contributing/testing/unit.rst

@@ -12,20 +12,6 @@ Integration Testing
 Cilium uses the standard `go test <https://golang.org/pkg/testing/>`__ framework.
 All new tests must use `the standard test framework`_.
 
-Historically, `gocheck <https://gopkg.in/check.v1>`__ has also been used. 
-Many tests are still written using ``gocheck``, which creates some
-unfortunate consequences:
-
-1. Adding a test helper requires writing two versions: one for ``testing.T``
-   and one for ``check.C``.
-
-2. Executing ``gocheck`` tests requires non-standard flags.
-
-For this reason ``gopkg.in/check.v1`` has switched to a fork called
-``github.com/cilium/checkmate``, which removes most of the problematic bits.
-You can migrate away from ``gocheck`` by following the procedure outlined
-in :ref:`migrate-gocheck`.
-
 .. _the standard test framework: https://github.com/cilium/cilium/issues/16860
 
 .. _integration_testing_prerequisites:
@@ -119,125 +105,3 @@ run this in a terminal next to your editor:
     $ watchtest pkg/policy
 
 This shell script depends on the ``inotify-tools`` package on Linux.
-
-.. _migrate-gocheck:
-
-Migrating tests off of ``gopkg.in/check.v1``
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-The Cilium codebase has historically used ``gopkg.in/check.v1`` to write unit and
-integration tests. Most of the functionality offered by that package is now
-present in `testing`_. What ``gocheck`` calls checkers are now available in
-``testify``, in either `assert`_ or `require`_ form.
-
-* ``check.Equals``: ``require.EqualValues``
-
-* ``check.HasLen``: ``require.Len``
-
-* ``check.ErrorMatches``: ``require.ErrorContains`` (doesn't support regex)
-
-* ``checker.Equals`` and ``checker.DeepEquals``: ``require.Equal``
-
-It's best to replace ``check.C.Assert`` with ``require`` calls instead of ``assert`` because the latter doesn't stop test execution if the assertion fails.
-
-``gopkg.in/check.v1`` has been replaced with ``github.com/cilium/checkmate``, which
-means that ``check.C`` now implements `testing.TB <https://pkg.go.dev/testing#TB>`__
-and can be passed to test helpers that take ``testing.TB``.
-
-The end goal is to remove all uses of ``checkmate`` from the codebase.
-To convert a ``gocheck`` test, use the following approach:
-
-1. Replace ``SetUp`` fixtures with helpers that take ``testing.TB``.
-
-2. Replace ``TearDown`` fixtures with calls to ``testing.TB.Cleanup()``,
-   possibly in the helper you added to replace ``SetUp``.
-
-3. Replace calls to ``c.Assert`` with ``require`` equivalents.
-
-4. Replace tests methods with a normal ``func TestHelloWorld(t *testing.T)``
-   function.
-
-Let's take an example from the ``gocheck`` documentation and migrate it:
-
-.. code-block:: go
-
-    package hello_test
-
-    import (
-        "testing"
-
-        . "gopkg.in/check.v1"
-    )
-
-    func Test(t *testing.T) { TestingT(t) }
-
-    type MySuite struct{}
-
-    var _ = Suite(&MySuite{})
-
-    func (s *MySuite) SetUpTest(c *C) {
-        // setup code
-    }
-
-    func (s *MySuite) TearDownTest(c *C) {
-        // cleanup code
-    }
-
-    func (s *MySuite) TestHelloWorld(c *C) {
-        c.Assert(42, Equals, "42")
-    }
-
-    type SomeOtherSuite struct{}
-
-    var _ = Suite(&SomeOtherSuite{})
-
-    func (s *SomeOtherSuite) TestTheRealAnswer(c *C) {
-        c.Assert("42", Equals, "42")
-    }
-
-After applying the previous rules you should end up with something like this:
-
-.. code-block:: go
-
-    package hello_test
-
-    import (
-        "testing"
-
-        . "github.com/cilium/checkmate"
-        "github.com/stretchr/testify/assert"
-    )
-
-    func Test(t *testing.T) { TestingT(t) }
-
-    func setupHelper(tb testing.TB) {
-        tb.Helper()
-
-        // setup code
-
-        tb.Cleanup(func() {
-            // cleanup code
-        })
-    }
-
-    func TestHelloWorld(t *testing.T) {
-        setupHelper(t)
-
-        require.Equal(t, 42, "42")
-    }
-
-    type SomeOtherSuite struct{}
-
-    var _ = Suite(&SomeOtherSuite{})
-
-    func (s *SomeOtherSuite) TestTheRealAnswer(c *C) {
-        require.Equal(c, "42", "42")
-    }
-
-As you can see we didn't get round to converting all tests yet.
-Since ``C`` now implements ``testing.TB`` we can call ``require.Equal`` from
-``TestTheRealAnswer()`` without problems.
-
-.. _assert: https://pkg.go.dev/github.com/stretchr/testify/assert
-.. _require: https://pkg.go.dev/github.com/stretchr/testify/require
-.. _testing: https://golang.org/pkg/testing/