tests: Update tests to use example profile picture.

So that we can stop using Tim's photo for tests, adds an open
license profile picture to use instead.

Updates tests that used `tim.png` to use the new example profile
picture, which is located in `static/images/test-images/avatars/`.

zerver/lib/dev_ldap_directory.py

@@ -25,7 +25,7 @@ def generate_dev_ldap_dir(mode: str, num_users: int = 8) -> Dict[str, Dict[str,
         ldap_data.append((name, email, phone_number, birthdate))
 
     profile_images = []
-    for path in glob.glob(os.path.join(static_path("images/landing-page/team"), "*")):
+    for path in glob.glob(os.path.join(static_path("images/test-images/avatars"), "*")):
         with open(path, "rb") as f:
             profile_images.append(f.read())
     ldap_dir = {}

zerver/tests/fixtures/ldap/directory.json

@@ -13,7 +13,7 @@
         "sn": ["Hamlet"],
         "homePhone": ["123456789"],
         "birthDate": ["1900-09-08"],
-        "jpegPhoto": "file:static/images/landing-page/team/tim.png"
+        "jpegPhoto": "file:static/images/test-images/avatars/example_profile_picture.png"
     },
 
     "uid=cordelia,ou=users,dc=zulip,dc=com": {
@@ -38,7 +38,7 @@
         "uid": ["newuser"],
         "sn": ["shortname"],
         "homePhone": ["a-new-number"],
-        "jpegPhoto": "file:static/images/landing-page/team/tim.png"
+        "jpegPhoto": "file:static/images/test-images/avatars/example_profile_picture.png"
     },
 
     "uid=newuser_splitname,ou=users,dc=zulip,dc=com": {

zerver/tests/test_auth_backends.py

@@ -6053,10 +6053,16 @@ class TestLDAP(ZulipLDAPTestCase):
             response = self.client_get(url)
             self.assertEqual(response.status_code, 200)
             with open(
-                os.path.join(settings.DEPLOY_ROOT, "static/images/landing-page/team/tim.png"), "rb"
+                os.path.join(
+                    settings.DEPLOY_ROOT,
+                    "static/images/test-images/avatars/example_profile_picture.png",
+                ),
+                "rb",
             ) as f:
-                tim = f.read()
-            self.assert_streaming_content(response, resize_avatar(tim, DEFAULT_AVATAR_SIZE))
+                example_avatar = f.read()
+            self.assert_streaming_content(
+                response, resize_avatar(example_avatar, DEFAULT_AVATAR_SIZE)
+            )
 
     @override_settings(AUTHENTICATION_BACKENDS=("zproject.backends.ZulipLDAPAuthBackend",))
     def test_login_success_when_user_does_not_exist_with_split_full_name_mapping(self) -> None: