chore: only allow triggers on pull requests (#30)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: DerekRoberts

README.md

@@ -80,11 +80,6 @@ Only Java is supported by this action.  Please see our [JavaScript action](https
     # Useful for consuming non-default branches, like in testing
     # Defants to empty, cloning the default branch
     branch: ""
-
-    # Bash array of events for limiting triggers, otherwise trigger automatically
-    # E.g. ("pull_request" "push" "workflow_dispatch")
-    # Defaults to only using triggers with pull requests
-    triggers_event: "('pull_request')"
 ```
 
 # Example, Single Directory with SonarCloud Analysis
@@ -200,10 +195,6 @@ After sign up, a token should be available from your project on the [SonarCloud]
 
 E.g. https://sonarcloud.io/project/configuration?id={<PROJECT>}&analysisMode=GitHubActions
 
-# Triggers and Triggers_Event
-
-Triggers are used to limit test running to only appropriate files are changed.  This is generally not desirable outside of pull requests, so `triggers_event` defaults to `("pull_request")`.  Override this behaviour by specifying a bash array using any of the many, many [event types GitHub provides](https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#push), e.g. `("branch_protection_rule" "workflow_dispatch" "push")`.
-
 # Feedback
 
 Please contribute your ideas!  [Issues] and [pull requests] are appreciated.

action.yml

@@ -53,10 +53,6 @@ inputs:
     description: Non-default branch to clone (used for testing this action)
     default: ""
 
-  triggers_event:
-    description: Events (array) to use with triggers; e.g. ("pull_request" "push" "workflow_dispatch")
-    default: "('pull_request')"
-
 runs:
   using: composite
   steps:
@@ -72,11 +68,11 @@ runs:
           exit 1
         fi
 
-    # Send triggers to diff action
+    # Send triggers to diff action, but only for pull requests
     - id: diff
       uses: bcgov/action-diff-triggers@v0.2.0
       with:
-        triggers: ${{ inputs.triggers }}
+        triggers: ${{ (github.event_name == 'pull_request' && inputs.triggers) || '' }}
         diff_branch: ${{ inputs.diff_branch }}
 
     - uses: actions/checkout@v4