Fix minor memory leaks in pg_dump.

Coverity reported the two oversights in getPublicationTables.
Valgrind found the one in determineNotNullFlags.

The mistakes in getPublicationTables seem too minor to be worth
back-patching.  determineNotNullFlags could be run enough times
to matter, but that code is new in v18.  So, no back-patch.

Author: tglsfdc

src/bin/pg_dump/pg_dump.c

@@ -4682,6 +4682,8 @@ getPublicationTables(Archive *fout, TableInfo tblinfo[], int numTables)
 				appendPQExpBufferStr(attribs, fmtId(attnames[k]));
 			}
 			pubrinfo[j].pubrattrs = attribs->data;
+			free(attribs);		/* but not attribs->data */
+			free(attnames);
 		}
 		else
 			pubrinfo[j].pubrattrs = NULL;
@@ -9424,6 +9426,7 @@ determineNotNullFlags(Archive *fout, PGresult *res, int r,
 					tbinfo->notnull_constrs[j] =
 						pstrdup(PQgetvalue(res, r, i_notnull_name));
 				}
+				free(default_name);
 			}
 		}
 	}