fix: Don't crash when unable to post comment to PR (#5669)
fix: Don't crash when unable to post comment to PR (#5669)

... by not ever posting such comments from this workflow.

There will be a separate PR for the other workflow that does post
comments, because it needs to be in the master branch.

Part of #5659.
mark-friedman/blockly,mark-friedman/blockly,mark-friedman/blockly,google/blockly,rachel-fenichel/blockly,rachel-fenichel/blockly,mark-friedman/blockly,rachel-fenichel/blockly,mark-friedman/blockly,rachel-fenichel/blockly,google/blockly,google/blockly,google/blockly,rachel-fenichel/blockly,mark-friedman/blockly,google/blockly,google/blockly,google/blockly,rachel-fenichel/blockly,rachel-fenichel/blockly