r/aws_servicecatalog_portfolio_share: revert additional not found check on read

```console
% AWS_ALTERNATE_PROFILE=terraform_team1_dev make t K=servicecatalog T=TestAccServiceCatalog_serial/PortfolioShare
make: Verifying source code with gofmt...
==> Checking that code complies with gofmt requirements...
make: Running acceptance tests on branch: 🌿 b-aws_servicecatalog_portfolio_share-sequential-processing 🌿...
TF_ACC=1 go1.24.8 test ./internal/service/servicecatalog/... -v -count 1 -parallel 20 -run='TestAccServiceCatalog_serial/PortfolioShare'  -timeout 360m -vet=off
2025/10/08 15:23:23 Creating Terraform AWS Provider (SDKv2-style)...
2025/10/08 15:23:23 Initializing Terraform AWS Provider (SDKv2-style)...

--- PASS: TestAccServiceCatalog_serial (216.76s)
    --- PASS: TestAccServiceCatalog_serial/PortfolioShare (216.76s)
        --- PASS: TestAccServiceCatalog_serial/PortfolioShare/basic (39.02s)
        --- SKIP: TestAccServiceCatalog_serial/PortfolioShare/sharePrincipals (0.54s)
        --- SKIP: TestAccServiceCatalog_serial/PortfolioShare/organizationalUnit (0.38s)
        --- PASS: TestAccServiceCatalog_serial/PortfolioShare/disappears (176.83s)
PASS
ok      github.com/hashicorp/terraform-provider-aws/internal/service/servicecatalog     223.513s
```

Author: jar-b

internal/service/servicecatalog/portfolio_share.go

@@ -199,7 +199,7 @@ func resourcePortfolioShareRead(ctx context.Context, d *schema.ResourceData, met
 
 	output, err := waitPortfolioShareReady(ctx, conn, portfolioID, shareType, principalID, waitForAcceptance, d.Timeout(schema.TimeoutRead))
 
-	if !d.IsNewResource() && (errs.IsA[*awstypes.ResourceNotFoundException](err) || tfresource.NotFound(err)) {
+	if !d.IsNewResource() && tfresource.NotFound(err) {
 		log.Printf("[WARN] Service Catalog Portfolio Share (%s) not found, removing from state", d.Id())
 		d.SetId("")
 		return diags