title: EF Core 3.1 have identity field without identity / remove identity increment
body: <p>There are a lot of questions of how to use fluent API to set a columns as an identity column using:</p>
  <p><code>.UseIdentityColumn()</code></p>
  <p>However, I need the opposite - the primary key field, needs to be the table identity (for UPSERTS) however, I'd like to remove the identity spec.</p>
  <p>In SSMS I can set the identity specification to <code>no</code> but I'd like to see if this is possible within the Fluent API.</p>
  <p>I've tried:</p>
  <p>Edit to update - the full code is:</p>
  <pre><code>builder.Entity&lt;ModelClass&gt;().HasKey(x =&gt; x.Id);
  builder.Entity&lt;ModelClass&gt;()
                  .Property(x =&gt; x.Id)
                  .ValueGeneratedNever()                
                  .HasAnnotation(&quot;DatabaseGenerated&quot;, DatabaseGeneratedOption.None);
  </code></pre>
  <p>So, the ID column still needs to be key to the table <code>.HasKey(x =&gt; x.Id)</code> - but without the identity spec</p>
  <p>The property Id is a key, and then told to not generate values. For me, in SQL server the table still has a &quot;Identity Specification&quot; = &quot;yes&quot; and then seed and increment values set.</p>