Don't add comments about API docs previews to PRs

Previously we've been adding comments to PRs modifying Solidity contracts about
available previews of the API documentation. As each push to the PR branch
results in one such comment, PRs with a lot of pushes get quite busy with a lot
of the similar comments. In the future it would be good to modify our
commenting mechanism so that it would just leave one comment per PR and update
it on each push. Until we do that we're turning off the PR commenting, to
increase readability.

Author: michalinacienciala

.github/workflows/contracts-ecdsa-docs.yml

@@ -47,7 +47,7 @@ jobs:
       projectDir: /solidity/ecdsa
       publish: false
       addTOC: false
-      commentPR: true
+      commentPR: false
       exportAsGHArtifacts: true
 
   # This job is needed to avoid a clash of `contracts-docs-publish` jobs for

.github/workflows/contracts-random-beacon-docs.yml

@@ -47,7 +47,7 @@ jobs:
       projectDir: /solidity/random-beacon
       publish: false
       addTOC: false
-      commentPR: true
+      commentPR: false
       exportAsGHArtifacts: true
 
   # This job will be triggered for releases which name starts with