Deprecate untested Tegile share driver

The driver was added in 2016, but it has had no 3rd party CI and it has
been untested. According to git log, the driver has not get any updates
specific to it.

Cinder already removed the Tegile driver[1] because of lack of CI.

[1] https://review.opendev.org/c/openstack/cinder/+/501333

Change-Id: I25a97ee23e5ce96ca0aec15941ad26763cd8cea0

manila/share/drivers/tegile/tegile.py

@@ -170,6 +170,9 @@ class TegileShareDriver(driver.ShareDriver):
     def __init__(self, *args, **kwargs):
         super(TegileShareDriver, self).__init__(False, *args, **kwargs)
 
+        LOG.warning('Tegile share driver has been deprecated and will be '
+                    'removed in a future release.')
+
         self.configuration.append_config_values(tegile_opts)
         self._default_project = (self.configuration.safe_get(
             "tegile_default_project") or 'openstack')

releasenotes/notes/deprecate-tegile-04c7466e29570ad5.yaml

@@ -0,0 +1,5 @@
+---
+deprecations:
+  - |
+    The Tegile share driver has been deprecated and will be removed in
+    a future release.