Revert "Add read_channel_content permission (#24018)" (#24114)

This reverts commit a19ce047ba.

server/channels/app/authorization_test.go

@@ -33,13 +33,11 @@ func TestCheckIfRolesGrantPermission(t *testing.T) {
 		{[]string{model.SystemAdminRoleId}, model.PermissionManageSystem.Id, true},
 		{[]string{model.SystemAdminRoleId}, "non-existent-permission", false},
 		{[]string{model.ChannelUserRoleId}, model.PermissionReadChannel.Id, true},
-		{[]string{model.ChannelUserRoleId}, model.PermissionReadChannelContent.Id, true},
 		{[]string{model.ChannelUserRoleId}, model.PermissionManageSystem.Id, false},
 		{[]string{model.SystemAdminRoleId, model.ChannelUserRoleId}, model.PermissionManageSystem.Id, true},
 		{[]string{model.ChannelUserRoleId, model.SystemAdminRoleId}, model.PermissionManageSystem.Id, true},
 		{[]string{model.TeamUserRoleId, model.TeamAdminRoleId}, model.PermissionManageSlashCommands.Id, true},
 		{[]string{model.TeamAdminRoleId, model.TeamUserRoleId}, model.PermissionManageSlashCommands.Id, true},
-		{[]string{model.ChannelGuestRoleId}, model.PermissionReadChannelContent.Id, true},
 	}
 
 	for _, testcase := range cases {