gha(linters): enable 7 more Python flake8 checks (#7005)

Author: jbampton

.github/linters/.flake8

@@ -15,10 +15,17 @@
 # specific language governing permissions and limitations
 # under the License.
 
+# E223 Tab before operator
+# E224 Tab after operator
+# E242 Tab after ','
+# E273 Tab after keyword
+# E274 Tab before keyword
+# E901 SyntaxError or IndentationError
+# E902 IOError
 # W291 Trailing whitespace
 # W292 No newline at end of file
 # W293 Blank line contains whitespace
 # W391 Blank line at end of file
 
 [flake8]
-select = W291,W292,W293,W391
+select = E223,E224,E242,E273,E274,E901,E902,W291,W292,W293,W391