Extract the bump-agent-versions workflow into a script (#4521)

When the script is in the multiline YAML it breaks the desired
formatting of the commit message.
Also editing this script separately is a better developer experience.

.github/workflows/bump-agent-versions.sh

@@ -0,0 +1,32 @@
+#!/bin/bash
+set -e
+
+version_requirements=$(mage integration:updateVersions)
+changes=$(git status -s -uno .agent-versions.json)
+if [ -z "$changes" ]
+then
+    echo "The versions file didn't change, skipping..."
+else
+    echo "The versions file changed"
+    open=$(gh pr list --repo "$GITHUB_REPOSITORY" --label="update-versions" --limit 1 --state open --base "$GITHUB_REF_NAME")
+    if [ -n "$open" ]
+    then
+        echo "Another PR for $GITHUB_REF_NAME is in review, skipping..."
+        exit 0
+    fi
+    git diff -p
+    git config --global user.name 'apmmachine'
+    git config --global user.email '[email protected]'
+    git add ".agent-versions.json"
+    git commit -m "[$GITHUB_REF_NAME](automation) Update .agent-versions.json" -m "This file is used for picking agent versions in integration tests.\n\nThe file's content is based on responses from https://www.elastic.co/api/product_versions and https://snapshots.elastic.co\n\nThe current update is generated based on the following requirements:\n\`\`\`json\n$version_requirements\n\`\`\`"
+    git push --set-upstream origin "update-agent-versions-$GITHUB_RUN_ID"
+    gh pr create \
+       --base "$GITHUB_REF_NAME" \
+       --fill-first \
+       --head "update-agent-versions-$GITHUB_RUN_ID" \
+       --label 'Team:Elastic-Agent' \
+       --label 'update-versions' \
+       --label 'skip-changelog' \
+       --label 'backport-skip' \
+       --repo $GITHUB_REPOSITORY
+fi

.github/workflows/bump-agent-versions.yml

@@ -33,33 +33,4 @@ jobs:
       - name: Update versions file
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        run: |
-          version_requirements=$(mage integration:updateVersions)
-          changes=$(git status -s -uno .agent-versions.json)
-          if [ -z "$changes" ]
-          then
-            echo "The versions file didn't change, skipping..."
-          else
-            echo "The versions file changed"
-            open=$(gh pr list --repo "$GITHUB_REPOSITORY" --label="update-versions" --limit 1 --state open --base "$GITHUB_REF_NAME")
-            if [ -n "$open" ]
-            then
-              echo "Another PR for $GITHUB_REF_NAME is in review, skipping..."
-              exit 0
-            fi
-            git diff -p
-            git config --global user.name 'apmmachine'
-            git config --global user.email '[email protected]'
-            git add ".agent-versions.json"
-            git commit -m "[$GITHUB_REF_NAME](automation) Update .agent-versions.json" -m "This file is used for picking agent versions in integration tests.\n\nThe file's content is based on responses from https://www.elastic.co/api/product_versions and https://snapshots.elastic.co\n\nThe current update is generated based on the following requirements:\n\`\`\`json\n$version_requirements\n\`\`\`"
-            git push --set-upstream origin "update-agent-versions-$GITHUB_RUN_ID"
-            gh pr create \
-              --base "$GITHUB_REF_NAME" \
-              --fill-first \
-              --head "update-agent-versions-$GITHUB_RUN_ID" \
-              --label 'Team:Elastic-Agent' \
-              --label 'update-versions' \
-              --label 'skip-changelog' \
-              --label 'backport-skip' \
-              --repo $GITHUB_REPOSITORY
-          fi
+        run: ./.github/workflows/bump-agent-versions.sh