fix: Allow aiven provider to compile without fork

Attempting to use the upstream provider directly fails due to the assert removed
here.

I believe this change is safe to make, despite affecting all providers, as the
assert causes tfgen to panic.

Background:

The Aiven provider has data sources such as:

> - `pg_partman_bgw__dot__interval` (String)
> - `pg_partman_bgw__dot__role` (String)
> - `pg_stat_statements__dot__track` (String)
(Copied from their changelog.)

The upstream provider uses a pair of routines to map `.` to `__dot__` and vice
versa, and the patch in our fork of Aiven modifies that mapping to avoid double
underscores:

pulumi/terraform-provider-aiven@296d9e0d

By allowing the bridge to generate the name, the upstream provider can be used
without requiring the fork. The casing behavior is preserved, and `__dot__` is
cased exactly as `_dot_` was before.

pkg/tfbridge/names.go

@@ -21,7 +21,6 @@ import (
 
 	"github.com/gedex/inflector"
 	"github.com/pulumi/pulumi/sdk/v3/go/common/resource"
-	"github.com/pulumi/pulumi/sdk/v3/go/common/util/contract"
 
 	shim "github.com/pulumi/pulumi-terraform-bridge/v3/pkg/tfshim"
 )
@@ -102,8 +101,6 @@ func TerraformToPulumiName(name string, sch shim.Schema, ps *SchemaInfo, upper b
 	casingActivated := false // tolerate leading underscores
 	for i, c := range name {
 		if c == '_' && casingActivated {
-			// skip underscores and make sure the next one is capitalized.
-			contract.Assertf(!nextCap, "Unexpected duplicate underscore: %v", name)
 			nextCap = true
 		} else {
 			if c != '_' && !casingActivated {