Remove raise_error negative block to fix RSpec warnings

Currently RSpec warns these specs like this:

```
WARNING: Using `expect { }.not_to raise_error(SpecificErrorClass)` risks false positives, since literally any other error would cause the
expectation to pass, including those raised by Ruby (e.g. `NoMethodError`, `NameError` and `ArgumentError`), meaning the code you are intending
to test may not even get reached. Instead consider using `expect { }.not_to raise_error` or `expect { }.to raise_error(DifferentSpecificErrorClass)`.
This message can be suppressed by setting: `RSpec::Expectations.configuration.on_potential_false_positives = :nothing`.
Called from /path/to/spec/lib/stripe/payment_intent_validator_spec.rb:53:in `block (7 levels) in <main>'.
```

The warnings are super accurate in this particular case: the inner
assertion is not actually getting reached due to a previous unrelated
error.

Since there's an inner assertion already, I think it's best to
completely remove to `raise_error` negative block, since it just hides
errors and buys us nothing.

By removing it, the underlying error surfaces:

```
  1) Stripe::PaymentIntentValidator#call as a guest when payment intent is valid valid non-3D credit cards are correctly handled behaves like payments intents from Visa returns payment intent id and does not raise
     Failure/Error:
       create(:payment, amount: payment_intent.amount, payment_method:,
                        response_code: payment_intent.id, source: pm_card)

     NoMethodError:
       undefined method `has_query_constraints?' for Stripe::PaymentMethod:Class

               elsif (klass || self.klass).has_query_constraints? || options[:query_constraints]
                                          ^^^^^^^^^^^^^^^^^^^^^^^
     Shared Example Group: "payments intents" called from ./spec/lib/stripe/payment_intent_validator_spec.rb:75
     # ./spec/lib/stripe/payment_intent_validator_spec.rb:16:in `block (3 levels) in <main>'
     # ./spec/lib/stripe/payment_intent_validator_spec.rb:19:in `block (3 levels) in <main>'
     # ./spec/lib/stripe/payment_intent_validator_spec.rb:53:in `block (7 levels) in <main>'
     # ./spec/base_spec_helper.rb:208:in `block (2 levels) in <main>'
     # ./spec/base_spec_helper.rb:155:in `block (3 levels) in <main>'
     # ./spec/base_spec_helper.rb:155:in `block (2 levels) in <main>'
     # -e:1:in `<main>'
```

spec/lib/stripe/payment_intent_validator_spec.rb

@@ -50,13 +50,11 @@ RSpec.describe Stripe::PaymentIntentValidator do
               Stripe::PaymentIntent.confirm(payment_intent.id)
             end
             it "returns payment intent id and does not raise" do
-              expect {
-                result = validator.call
-                expect(result).to eq(
-                  "this doesn't affect the spec because it never runs, due to a previous error." \
-                  "Yet, since this is wrapper in a negative raise_error block, it still passes"
-                )
-              }.not_to raise_error Stripe::StripeError
+              result = validator.call
+              expect(result).to eq(
+                "this doesn't affect the spec because it never runs, due to a previous error." \
+                "Yet, since this is wrapper in a negative raise_error block, it still passes"
+              )
             end
 
             it "captures the payment" do
@@ -197,13 +195,11 @@ RSpec.describe Stripe::PaymentIntentValidator do
               Stripe::PaymentIntent.confirm(payment_intent.id)
             end
             it "returns payment intent id and does not raise" do
-              expect {
-                result = validator.call
-                expect(result).to eq(
-                  "this doesn't affect the spec because it never runs, due to a previous error." \
-                  "Yet, since this is wrapper in a negative raise_error block, it still passes"
-                )
-              }.not_to raise_error Stripe::StripeError
+              result = validator.call
+              expect(result).to eq(
+                "this doesn't affect the spec because it never runs, due to a previous error." \
+                "Yet, since this is wrapper in a negative raise_error block, it still passes"
+              )
             end
 
             it "captures the payment" do