Making WordPress code blocks display the right size

I started using WordPress’s block code with syntax highlighting. Unfortunately the text was being displayed too large.

What I wanted

x509_attribute_type = {
  "x509_attr_unknown"   : 0,  
  "x509_attr_name"      : 1, 
  "x509_attr_surname"   : 2,   
  "x509_attr_givenName" : 3,   
  "x509_attr_initials"  : 4,
  ...  
}

What I got

x509_attribute_type = {
  "x509_attr_unknown"   : 0,  
  "x509_attr_name"      : 1, 
  "x509_attr_surname"   : 2,   
  "x509_attr_givenName" : 3,   
  "x509_attr_initials"  : 4,
  ...  
}

There were “helpful” suggestions such as changing the CSS, but these did not work for me.
What did work (but involved several clicks) is

• create a pre-formatted block
• paste the data
• in the FONT SIZE box on the right hand side click S
• go back to your block, and make it into a code block
• from the pull down list of languages, select the language you want
• It should not display the code in the right sized font

What the above actions have done is to put <pre class=”wp-block-code has-small-font-size”> … </pre> around the code snippet, which is another solution.