Replace http://example.com with https://example.com in update test fixtures

@garvitasakhrani, Welcome to Drupal! Thank you for working on this.

The changes made are what was asked for in the issue summary. Well done.

Now, unfortunately, there are failed tests which need to be resolved. Right now there is a red circle next to the link to MR for this issue at the end of the Issue Summary. If you click on that link, you get the an overview of all the tests that ran in our pipeline. Then, Select 'Tests' and scroll down the list to find which group of tests had failures. Here, it is 'PHPUnit Functional'. Select 'PHPUnit Functional' and the failed tests are shown at the top of the list. And selecting 'View details' does just that, it shows the error message and line where the failure occurred. I suggest you find time to explore the GitLab UI, if you are not already familiar with it. Testing is an integral part of Drupal core development.

As, for the failure, it is because the actual tests are still using 'http://' type URLs. So, those need to be changed as well. All the Functional tests are in the directory core/modules/update/test/src/Functional. So, we just need a new command to find those files and run sed. I have added those to the 'Proposed resolution' section of the Issue Summary'

Not thinking about the tests was an oversight on my part when I created this issue.

@garvitasakhrani, can you make the change to the test files?

@garvitasakhrani, thanks for the updates.

I applied the diff to 11.x HEAD, and searched for instances of http://example.com and http://www.example.com in the Update status module.

$ git grep http://example.com core/modules/update/
(11.x)$ 

$ git grep http://www.example.com core/modules/update/
core/modules/update/tests/src/Unit/UpdateFetcherTest.php:    $this->mockConfigFactory = $this->getConfigFactoryStub(['update.settings' => ['fetch_url' => 'http://www.example.com']]);
core/modules/update/tests/src/Unit/UpdateFetcherTest.php:    $project['info']['project status url'] = 'http://www.example.com';
core/modules/update/tests/src/Unit/UpdateFetcherTest.php:    $expected = "http://www.example.com/{$project['name']}/current";
core/modules/update/tests/src/Unit/UpdateFetcherTest.php:    $expected = "http://www.example.com/{$project['name']}/current";
core/modules/update/tests/src/Unit/UpdateFetcherTest.php:    $expected = "http://www.example.com/{$project['name']}/current";
core/modules/update/tests/src/Unit/UpdateFetcherTest.php:    $project['info']['project status url'] = 'http://www.example.com/?project=';
core/modules/update/tests/src/Unit/UpdateFetcherTest.php:    $expected = "http://www.example.com/?project=/{$project['name']}/current";

There are still instances of http://www.example.com in a Unit test but those are not using the test fixtures that are similar to the d.o release history XML, so technically out of scope. They will be done in another issue of the parent.

These changes are correct and in scope. Thanks @garvitasakhrani.

The next step here is a review. For this issue that is also novice level. I have updated the issue summary with information for that.