Don't fail if unicode.org isn't talking to us
Revert "Use a type object for type casting behavior on SQLite3"
Merge pull request #16054 from rails/revert-16003-sg-refactor-sqlite3-strings

Revert "Use a type object for type casting behavior on SQLite3"
Add a `required` option to singular associations

In addition to defining the association, a `required` association will
also have its presence validated.

Before:

```ruby
belongs_to :account
validates_presence_of :account
```

After:

```ruby
belongs_to :account, required: true
```

This helps to draw a distinction between types of validations, since
validations on associations are generally for data integrity purposes,
and aren't usually set through form inputs.
Merge pull request #16056 from sgrif/sg-required-associations

Add a `required` option to singular associations
CHANGELOG and release notes entry for #16056
Add release notes entry for #15819 [ci skip]
Use the type object for quoting PG Ranges
`Time.today` -> `Date.today` in guides. [ci skip]

Removed mentions of non-existent methods, also added a mention for
`Date.current`, which is analagous to `Time.current`. Closes #16061.
Remove *all* references to `Time.yesterday` [ci skip]
Only reference time specific methods in the time section [ci skip]
Merge pull request #16035 from sgrif/sg-range-types

Use the type object for quoting PG Ranges