[DOCS] The "Updating Drupal" section may need updating for Drupal 9

[ysuarez]

• If applicable, link to the documentation page relevant to your issue below.

https://islandora.github.io/documentation/technical-documentation/updating_drupal/

• If this is a request for new documentation, where in the existing documentation does this documentation belong?

n/a

• Describe your documentation request.

We should update the content for updating Drupal 9 core and Drupal modules using composer, since the current "Updating Drupal" has information that may be more geared for Drupal 8. As well as using Drupal 8 documentation links, that thankfully are redirecting to some Drupal 9 doc pages on drupal.org.

• Which version of islandora are you using?

Islandora 2 installed via ISLE2

• What user roles is this documentation intended for?

Developer, Systems Administrator

• What implementations of islandora does this documentation request apply to?

Islandora 2

Any related open or closed issues to this bug report?

Screenshots:

[ysuarez]

I just retyped the title of this issue, no other changes made since I just realized that I did not write the title to this issue correctly.