Changing runtime on doc page for one example changes it all for examples

[filmaj]

Describe the issue
Some individual code blocks on various pages in the docs have a dropdown that lets you pick a runtime to see the example code in (usually JS, Ruby, Python). If there are multiple such code blocks on a single page, if you change the example in one code block, all code blocks also switch their runtime. Additionally, when this occurs, the dropdown does not update for the other code blocks that changed their runtime.

Steps to reproduce
Steps to reproduce the behavior:

1. Go to https://arc.codes/primitives/http .
2. Scroll down to bottom of 'Provisioning HTTP functions' section.
3. Click on the code example dropdown and select a runtime other than JS.
4. Code block language changes as expected. Cool.
5. Scroll down to 'Examples' section.
6. Note that the code block in this section has also changed runtime, even though we didn't change the dropdown for this code block.
7. Note additionally that the dropdown value has not changed (it is still JS), but the code block language has changed.

Expected behavior
Change runtime in one code block, the change should apply only to that code block. Alternatively, if the change should apply to all code blocks, then we should update the dropdowns for all code blocks to reflect that correct runtime.