[release/0.9]Update CI

Incorporate several CI changes from multiple PRs:

 - microsoft#1632
 - microsoft#1752
 - microsoft#1755
 - microsoft#1799
 - microsoft#1820
 - microsoft#1836
 - microsoft#1853
 - microsoft#1854

It is easier to checkout the changes directly rather than cherry-pick
commits and undo any changes that affect code not backported to this
release.

Signed-off-by: Hamza El-Saawy <hamzaelsaawy@microsoft.com>

.gitattributes

@@ -1 +1,3 @@
-* text=auto eol=lf
+* text=auto eol=lf
+vendor/** -text
+test/vendor/** -text