removed forgotten Qt v5 related comments

[skip ci]

Author: silverqx

tests/README.md

@@ -13,7 +13,3 @@ The `tst_SchemaBuilder::createTable_Comment()` test method hardly depends on the
 ```
 search_path = public (set by the env. variable DB_PGSQL_SEARCHPATH = public)
 ```
-
-### Notes
-
-The `tst_Migrate` is not testing the Qt 5 `QSQLITE` driver because it doesn't support `ALTER TABLE DROP COLUMN`, support for dropping columns was added in the SQLite v3.35.0 as is described in the [release notes](https://www.sqlite.org/releaselog/3_35_0.html).

tests/auto/functional/tom/migrate/tst_migrate.cpp

@@ -165,9 +165,6 @@ namespace
 // NOLINTBEGIN(readability-convert-member-functions-to-static)
 void tst_Migrate::initTestCase()
 {
-    /* Testing of the Qt 5 QSQLITE driver is excluded because it doesn't support
-       ALTER TABLE DROP COLUMN, support for dropping columns was added
-       in the SQLite v3.35.0. */
     m_connections = Databases::createConnections({Databases::MYSQL,
                                                   Databases::MARIADB,
                                                   Databases::POSTGRESQL,