Trim the test matrix on Travis for 5.3-5.5 branches

[desrosj]

It's time to trim the test matrix for the 5.3-5.5 branches.

Following the practices for older branches established in previous tickets (#41707, #42626, #42387, #48413), these changes should be made for 5.3 & 5.4:

• Remove PHP jobs for PHP 7.1, 7.2, and 7.3 without Memcached.

For 5.3-5.5 branches:

• Remove all allowed failures (these will never be fixed to pass).

We could also remove the E2E test job as well. There is currently only 1 E2E test present, and it only confirms that the test suite run.

[desrosj]

In 49497:

Build/Test Tools: Remove jobs that are allowed to fail for the 5.5 branch.

Because PHP 8 support will not be backported to the 5.5 branch, the test job in the Travis matrix will never pass, making it unnecessary to continue running.

See #51705.

[desrosj]

In 49498:

Build/Test Tools: Trim the test matrix on Travis for the 5.4 branch.

This removes the PHP 7.3 (without Memcached), 7.2, and 7.1 jobs. It also removes the PHP 8 and PHP compatibility jobs. These were failing, and they will not be fixed in older branches.

See #51705.

[desrosj]

In 49499:

Build/Test Tools: Trim the test matrix on Travis for the 5.3 branch.

This removes the PHP 7.3 (without Memcached), 7.2, and 7.1 jobs. It also removes the PHP 8 and PHP compatibility jobs. These were failing, and they will not be fixed in older branches.

See #51705.

[desrosj]

We could also remove the E2E test job as well. There is currently only 1 E2E test present, and it only confirms that the test suite run.

Leaving open for feedback on this change before committing.

[johnbillion]

Yes this should be removed. When the time comes that we have useful E2E tests they should remain in place in older branches.

[desrosj]

In 49500:

Build/Test Tools: Remove the E2E test job from the 5.5 branch.

The E2E test job does not currently perform any meaningful tests, so continuing to run them is not necessary for older branches.

Props johnbillion.
See #51705.

[desrosj]

In 49501:

Build/Test Tools: Fix Travis configuration error.

Follow up to [49500].

See #51705.

[desrosj]

In 49502:

Build/Test Tools: Remove the E2E test job from the 5.4 branch.

The E2E test job does not currently perform any meaningful tests, so continuing to run them is not necessary for older branches.

Props johnbillion.
See #51705.

[desrosj]

In 49503:

Build/Test Tools: Remove the E2E test job from the 5.3 branch.

The E2E test job does not currently perform any meaningful tests, so continuing to run them is not necessary for older branches.

Props johnbillion.
Fixes #51705.