CI: Restore MiniInternetTestCase

[lschulz]

Add MiniInternetTestCase, IPAnyCastTestCase, and HostMgmtTestCase test cases to the CI pipeline.

Replaces the real world AS ping test in MiniInternetTestCase with an HTTP GET test that can get through the firewall of a GitHub action runner.

[lschulz]

MiniInternetTestCase fails with

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FAIL: test_internet_connection (internet.mini_internet.MiniInternetTestCase.MiniInternetTestCase)
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Traceback (most recent call last):
  File "/home/runner/work/seed-emulator/seed-emulator/tests/internet/mini_internet/MiniInternetTestCase.py", line 25, in test_internet_connection
    self.assertTrue(self.ping_test(self.source_host, ip))
AssertionError: False is not true
----------------------------------------------------------------------

IPAnyCastTestCase and HostMgmtTestCase also fail.

MiniInternetTestCase passes on my machine if a go back to commit 7e71113, so the problem was probably introduced since then.

@amdfxlucas could you take a look?