Python: Treat SyntaxErrors as warnings in diagnostics

Rename going to happen in second commit, so git doesn't get too confused

I don't actually recall where to lookup that warning is 1, and error is
2, but I took this from
https://github.com/github/codeql/pull/6830/files#diff-460fc20823ced3b074784db804f2d4d6cfcad4f23fe5d264dc7496c782629a2eR121-R123

Author: RasmusWL

python/ql/src/Diagnostics/ExtractionErrors.ql

@@ -1,23 +1,36 @@
 /**
- * @name Python extraction errors
- * @description List all extraction errors for Python files in the source code directory.
+ * @name Python extraction warnings
+ * @description List all extraction warnings for Python files in the source code directory.
  * @kind diagnostic
- * @id py/diagnostics/extraction-errors
+ * @id py/diagnostics/extraction-warnings
  */
 
 import python
 
 /**
- * Gets the SARIF severity for errors.
+ * Gets the SARIF severity for warnings.
  *
- * See point 3.27.10 in https://docs.oasis-open.org/sarif/sarif/v2.0/sarif-v2.0.html for
- * what error means.
+ * See https://docs.oasis-open.org/sarif/sarif/v2.1.0/csprd01/sarif-v2.1.0-csprd01.html#_Toc10541338
  */
-int getErrorSeverity() { result = 2 }
+int getWarningSeverity() { result = 1 }
 
+// The spec
+// https://docs.oasis-open.org/sarif/sarif/v2.1.0/csprd01/sarif-v2.1.0-csprd01.html#_Toc10541338
+// defines error and warning as:
+//
+// "error": A serious problem was found. The condition encountered by the tool resulted
+// in the analysis being halted or caused the results to be incorrect or incomplete.
+//
+// "warning": A problem that is not considered serious was found. The condition
+// encountered by the tool is such that it is uncertain whether a problem occurred, or
+// is such that the analysis might be incomplete but the results that were generated are
+// probably valid.
+//
+// so SyntaxErrors are reported at the warning level, since analysis might be incomplete
+// but the results that were generated are probably valid.
 from SyntaxError error, File file
 where
   file = error.getFile() and
   exists(file.getRelativePath())
 select error, "Extraction failed in " + file + " with error " + error.getMessage(),
-  getErrorSeverity()
+  getWarningSeverity()