chore(deps): update slackapi/slack-github-action action to v1.27.1

Author: renovate[bot]

.github/workflows/build-nightly.yml

@@ -174,7 +174,7 @@ jobs:
     steps:
       - name: Post to Slack
         id: slack
-        uses: slackapi/slack-github-action@v1.21.0
+        uses: slackapi/slack-github-action@v1.27.1
         with:
           channel-id: ${{ secrets.SLACK_CHANNEL_ID }}
           slack-message: ":thumbsup: VR Nightly build succeeded: \n
@@ -201,7 +201,7 @@ jobs:
     steps:
       - name: Post to Slack
         id: slack
-        uses: slackapi/slack-github-action@v1.21.0
+        uses: slackapi/slack-github-action@v1.27.1
         with:
           # Slack channel id, channel name, or user id to post message.
           # See also: https://api.slack.com/methods/chat.postMessage#channels

.github/workflows/main.yml

@@ -869,7 +869,7 @@ jobs:
 
       - name: Post to a Slack channel
         id: slack
-        uses: slackapi/slack-github-action@v1.23.0
+        uses: slackapi/slack-github-action@v1.27.1
         with:
           channel-id: ${{ secrets.SLACK_CHANNEL_ID }}
           slack-message: |

.github/workflows/pre-merge-tests.yml

@@ -327,7 +327,7 @@ jobs:
     steps:
       - name: Post to a Slack channel
         id: slack
-        uses: slackapi/slack-github-action@v1.23.0
+        uses: slackapi/slack-github-action@v1.27.1
         with:
           # Slack channel id, channel name, or user id to post message.
           # See also: https://api.slack.com/methods/chat.postMessage#channels