Clean up usage script

[blink1073]

Remove redundant calls in usage CI script.

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[blink1073]

This is partially to see if I can replicate the errors I'm seeing in #7618, which seem to be unrelated to that PR.

[blink1073]

First build failed on the filebrowser example test with:

/opt/hostedtoolcache/Python/3.6.9/x64/share/jupyter/lab/example_test/chrome-example-test.js:69
    throw up;
    ^

Error: Failed to launch chrome!
Inconsistency detected by ld.so: dl-tls.c: 493: _dl_allocate_tls_init: Assertion `listp->slotinfo[cnt].gen <= GL(dl_tls_generation)' failed!

[blink1073]

That failure was transient, and now this passes. I can't for the life of my figure out why #7618 would have any affect on sessions tests, it only touches code further up the stack.