This PR fixes the following incorrect autocorrect for `Lint/RedundantTypeConversion`
when using parentheses with no arguments or any arguments.

## Case 1: Parentheses with no arguments

First, this applies to parentheses with no arguments.

```console
$ echo '{k => v}.to_h()' | bundle exec rubocop --stdin test.rb -a --only Lint/RedundantTypeConversion
Inspecting 1 file
F

Offenses:

test.rb:1:9: F: Lint/Syntax: unexpected token tLPAREN2
(Using Ruby 2.7 parser; configure using TargetRubyVersion parameter, under AllCops)
{k => v}()
        ^
test.rb:1:10: W: [Corrected] Lint/RedundantTypeConversion: Redundant to_h detected.
{k => v}.to_h()
         ^^^^

1 file inspected, 2 offenses detected, 1 offense corrected
====================
{k => v}()
```

It is currently autocorrected to an invalid syntax with unnecessary parentheses.
Since this case is syntactically valid, it will be updated to the correct form `{k => v}` without parentheses.

## Case 2: Parentheses with arguments

Next, the case with arguments.

```console
$ echo '{k => v}.to_h(arg)' | bundle exec rubocop --stdin test.rb -a --only Lint/RedundantTypeConversion
Inspecting 1 file
F

Offenses:

test.rb:1:9: F: Lint/Syntax: unexpected token tLPAREN2
(Using Ruby 2.7 parser; configure using TargetRubyVersion parameter, under AllCops)
{k => v}(arg)
        ^
test.rb:1:10: W: [Corrected] Lint/RedundantTypeConversion: Redundant to_h detected.
{k => v}.to_h(arg)
         ^^^^

1 file inspected, 2 offenses detected, 1 offense corrected
====================
{k => v}(arg)
```

This case also results in an incorrect autocorrection. However, when arguments are present,
the method should be assumed to be either overridden or still under programming, and thus ignored.
In any case, it cannot be considered safely removable or redundant.