[Core] Support filename and environment variable completion (#11817)

az.completion

@@ -18,4 +18,4 @@ _python_argcomplete() {
         compopt -o nospace
     fi
 }
-complete -o nospace -F _python_argcomplete "az"
+complete -o nospace -o default -o bashdefault -F _python_argcomplete "az"

src/azure-cli/HISTORY.rst

@@ -7,6 +7,10 @@ Release History
 
 * Support app creation/update with the new sku name ST0, ST1, ST2.
 
+**Misc**
+
+* Fix #6371: Support filename and environment variable completion in Bash
+
 2.0.80
 ++++++