fix: remove unsupported MongoDB ODM Bundle ^3.0 dependency

[buffcode]

Removes unsupported doctrine/mongodb-odm-bundle:^3.0 dependency.

Why?

• this bundle relies on doesntmattr/mongodb-migrations:^3.0 (link)
• doesntmattr/mongodb-migrations:^3.0 makes use of DocumentManager::getClient (link)
• DocumentManager::getClient was added in doctrine/mongodb-odm 2.x.
• latest doctrine/mongodb-odm-bundle (v3.6.2) only supports doctrine/mongodb-odm:^1.2

Ergo this bundle should not have doctrine/mongodb-odm-bundle:^3.0 as supported dependency, as it will install but fail to work with the following set:

{
  "require": {
    "doesntmattr/mongodb-migrations": "^3.0",
    "doctrine/mongodb-odm-bundle": "^3.6"
  }
}