spec: Unskip flaky syllabus_teacher_spec example
spec: Unskip flaky syllabus_teacher_spec example

Unable to re-produce the flakiness in this test, this
commit un-skips them so we can monitor them and address them
if they are still flaky.

refs LS-2286
flag=none

Change-Id: Ie564d8654526577b8582d19d3fbc60a25023dc59
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/272351
Tested-by: Service Cloud Jenkins <9144042a601061f88f1e1d7a1753ea3e2972119d@instructure.com>
Reviewed-by: Robin Kuss <0b206b54367b2de0334896ea45826f0e3194bd35@instructure.com>
QA-Review: Robin Kuss <0b206b54367b2de0334896ea45826f0e3194bd35@instructure.com>
Product-Review: Luis Oliveira <4ec7209c0a6350a2c3877fe0e8e120f972fc692a@instructure.com>

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