Some tests are functionally disabled due to if $TRAVIS

[bk2204]

We have some tests in our testsuite that are functionally disabled because they run if $TRAVIS, which is always true if the TRAVIS environment variable is not set (fun shell fact!). Many of these deal with our TLS certificate handling, and they are broken in CI for various reasons depending on the OS.

We should probably investigate what's wrong and how to fix it, since these tests are never run unless TRAVIS is set to a shell command returning false. I should note that at least some of them pass on my Ubuntu 23.10 laptop, so simply reproducing on Linux is not sufficient to trigger the problem.

[chrisd8088]

I've discovered that if $TRAVIS problem myself in the past and have a stale set of updates to the test suite to remove the variable, but it's been about 18 months since I looked at it, so let me dust that off.

[bk2204]

I had discovered it in the past as well and tried to open a PR (#5615), but got distracted with other things after everything got angry and red. I very much appreciate any assistance you can offer here.

I anticipated you might inquire about it in #5657, which adds a more abbreviated adjacent test, so I thought I'd document it so we didn't lose track of it in the PR comments.