feat(mysql): add support for MySQL v8 (sequelize#13618)

This is a dummy commit so that the message appears in the changelog

fix(types): allow any values in `isIn` validator (sequelize#12962)

* fix(types): allow any values in `isIn` validator

* test(types): isIn/notIn validation type tests

Co-authored-by: Sascha Depold <[email protected]>

fix(deps): upgrade to secure versions of dev deps (sequelize#13549)

fix(dependency): upgrade validator (sequelize#13350)

meta: empty commit to rerun ci

meta: forbid auto major version release

fix(types): fix `Model.prototype.previous()` (sequelize#13042)

docs(upsert): improve return description

fix(types): allow bigints in `WhereValue` (sequelize#13028)

Co-authored-by: Pedro Augusto de Paula Barbosa <[email protected]>

fix(mysql): release connection on deadlocks (sequelize#13102)

* test(mysql, mariadb): improve transaction tests

- Greatly improve test for `SELECT ... LOCK IN SHARE MODE`
- Greatly improve test for deadlock handling

* fix(mysql): release connection on deadlocks

This is a follow-up for a problem not covered by sequelize#12841.

* refactor(mariadb): `query.js` similar to mysql's

* Update comments with a reference to this PR