rebase: bump github.com/Azure/azure-sdk-for-go/sdk/azidentity

Bumps [github.com/Azure/azure-sdk-for-go/sdk/azidentity](https://github.com/Azure/azure-sdk-for-go) from 1.5.1 to 1.6.0.
- [Release notes](https://github.com/Azure/azure-sdk-for-go/releases)
- [Changelog](https://github.com/Azure/azure-sdk-for-go/blob/main/documentation/release.md)
- [Commits](https://github.com/Azure/azure-sdk-for-go/compare/sdk/internal/v1.5.1...sdk/azcore/v1.6.0)

---
updated-dependencies:
- dependency-name: github.com/Azure/azure-sdk-for-go/sdk/azidentity
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

vendor/github.com/AzureAD/microsoft-authentication-library-for-go/apps/public/public.go

@@ -217,11 +217,13 @@ func WithClaims(claims string) interface {
 func WithAuthenticationScheme(authnScheme AuthenticationScheme) interface {
 	AcquireSilentOption
 	AcquireInteractiveOption
+	AcquireByUsernamePasswordOption
 	options.CallOption
 } {
 	return struct {
 		AcquireSilentOption
 		AcquireInteractiveOption
+		AcquireByUsernamePasswordOption
 		options.CallOption
 	}{
 		CallOption: options.NewCallOption(
@@ -231,6 +233,8 @@ func WithAuthenticationScheme(authnScheme AuthenticationScheme) interface {
 					t.authnScheme = authnScheme
 				case *interactiveAuthOptions:
 					t.authnScheme = authnScheme
+				case *acquireTokenByUsernamePasswordOptions:
+					t.authnScheme = authnScheme
 				default:
 					return fmt.Errorf("unexpected options type %T", a)
 				}
@@ -349,6 +353,7 @@ func (pca Client) AcquireTokenSilent(ctx context.Context, scopes []string, opts
 // acquireTokenByUsernamePasswordOptions contains optional configuration for AcquireTokenByUsernamePassword
 type acquireTokenByUsernamePasswordOptions struct {
 	claims, tenantID string
+	authnScheme      AuthenticationScheme
 }
 
 // AcquireByUsernamePasswordOption is implemented by options for AcquireTokenByUsernamePassword
@@ -374,6 +379,9 @@ func (pca Client) AcquireTokenByUsernamePassword(ctx context.Context, scopes []s
 	authParams.Claims = o.claims
 	authParams.Username = username
 	authParams.Password = password
+	if o.authnScheme != nil {
+		authParams.AuthnScheme = o.authnScheme
+	}
 
 	token, err := pca.base.Token.UsernamePassword(ctx, authParams)
 	if err != nil {