Fix 22053: Deprecate typeless catch at the parser level

[Geod24]

Type-less catch was previously deprecated only at the semantic level.
This is usually good, because it avoids spurious deprecations being triggered
in versioned-out code or generally unused (uninstantiated) code,
or in code that is 'deprecated'.
However, the syntax has been deprecated for years now, and should ultimately
be removed from the parser, but while validating the grammar, it was found that
the deprecation message didn't actually trigger in templated code, even instantiated.
While we could fix it by triggering a deprecation only when the code is instantiated,
this would still prevent us from removing support for parsing it.
Instead, add a deprecation in the parser, so that code that wasn't caught before will be.
The existing error is left in place, ensuring we don't regress.

[dlang-bot]

Thanks for your pull request, @Geod24!

Bugzilla references

Auto-close	Bugzilla	Severity	Description
✓	22053	normal	`catch {` not rejected while in a template

Testing this PR locally

If you don't have a local development environment setup, you can use Digger to test this PR:

dub run digger -- build "master + dmd#12721"

[Geod24]

Changed because if token.value == TOK.leftCurly, then token.value != TOK.leftParenthesis.

[WalterBright]

P.S. Thanks for the nice explanation.