Ensure more specialised exceptions are raised in PyQGIS

instead of the generic QgsException one
Refs warning in #55481 (comment)

```
/tmp/work/geography/qgis/work/qgis-3.28.13/build/python/core/build/_core/sip_corepart0.cpp:38168: warning: exception of type 'QgsProviderConnectionException' will be caught
38168 |             catch (QgsProviderConnectionException &sipExceptionRef)
      |
/tmp/work/geography/qgis/work/qgis-3.28.13/build/python/core/build/_core/sip_corepart0.cpp:38158: warning:    by earlier handler for 'QgsException'
38158 |             catch (QgsException &sipExceptionRef)
```

python/core/qgsexception.sip

@@ -22,51 +22,57 @@
 %End
 };
 
-%Exception QgsException(SIP_Exception) /PyName=QgsException/
+%Exception QgsProviderConnectionException(SIP_Exception) /PyName=QgsProviderConnectionException/
 {
 %TypeHeaderCode
 #include <qgsexception.h>
 %End
 %RaiseCode
   SIP_BLOCK_THREADS
-  PyErr_SetString(sipException_QgsException, sipExceptionRef.what().toUtf8().constData() );
+  PyErr_SetString(sipException_QgsProviderConnectionException, sipExceptionRef.what().toUtf8().constData() );
   SIP_UNBLOCK_THREADS
 %End
 };
 
-
-%Exception QgsProviderConnectionException(SIP_Exception) /PyName=QgsProviderConnectionException/
+%Exception QgsNotSupportedException(SIP_Exception) /PyName=QgsNotSupportedException/
 {
 %TypeHeaderCode
 #include <qgsexception.h>
 %End
 %RaiseCode
   SIP_BLOCK_THREADS
-  PyErr_SetString(sipException_QgsProviderConnectionException, sipExceptionRef.what().toUtf8().constData() );
+  PyErr_SetString(sipException_QgsNotSupportedException, sipExceptionRef.what().toUtf8().constData() );
   SIP_UNBLOCK_THREADS
 %End
 };
 
-%Exception QgsNotSupportedException(SIP_Exception) /PyName=QgsNotSupportedException/
+%Exception QgsSettingsException(SIP_Exception) /PyName=QgsSettingsException/
 {
 %TypeHeaderCode
 #include <qgsexception.h>
 %End
 %RaiseCode
   SIP_BLOCK_THREADS
-  PyErr_SetString(sipException_QgsNotSupportedException, sipExceptionRef.what().toUtf8().constData() );
+  PyErr_SetString(sipException_QgsSettingsException, sipExceptionRef.what().toUtf8().constData() );
   SIP_UNBLOCK_THREADS
 %End
 };
 
-%Exception QgsSettingsException(SIP_Exception) /PyName=QgsSettingsException/
+// IMPORTANT -- QgsException MUST be last listed, or it will greedily prevent the more
+// specialized exceptions from being raised
+
+%Exception QgsException(SIP_Exception) /PyName=QgsException/
 {
 %TypeHeaderCode
 #include <qgsexception.h>
 %End
 %RaiseCode
   SIP_BLOCK_THREADS
-  PyErr_SetString(sipException_QgsSettingsException, sipExceptionRef.what().toUtf8().constData() );
+  PyErr_SetString(sipException_QgsException, sipExceptionRef.what().toUtf8().constData() );
   SIP_UNBLOCK_THREADS
 %End
 };
+
+// IMPORTANT -- QgsException MUST be last listed, or it will greedily prevent the more
+// specialized exceptions from being raised
+