[.github] - refactor: mention workflow author in slack (#8967)

* [.github] - refactor: simplify retrieval of commit author information in slack-notify action

 - Use the GitHub actor as the commit author name and email instead of extracting from the git log
 - Set the author email to a no-reply GitHub address associated with the GitHub actor

* [.github/.mailmap] - refactor: streamline mailmap and GitHub action for Slack notifications

 - Modified the GitHub action to look up the author email using the improved mailmap
 - Simplified the mailmap file to map GitHub usernames directly to their dust email addresses

* [.mailmap] - refactor: clean up trailing whitespace

 - Remove the unnecessary empty line at the end of the .mailmap file

.github/actions/slack-notify/action.yml

@@ -29,27 +29,20 @@ outputs:
 runs:
   using: "composite"
   steps:
-    - name: Get author email
+    - name: Get author info
       if: inputs.step == 'start'
       id: author
       shell: bash
       run: |
-        # Get last commit author name and email
-        AUTHOR_NAME=$(git log -1 --format='%an')
-        AUTHOR_EMAIL=$(git log -1 --format='%ae')
+        AUTHOR_NAME="${{ github.actor }}"
 
-        if ! CANONICAL=$(git check-mailmap "$AUTHOR_NAME <$AUTHOR_EMAIL>" 2>/dev/null); then
-          echo "email=$AUTHOR_EMAIL" >> $GITHUB_OUTPUT
-          echo "name=$AUTHOR_NAME" >> $GITHUB_OUTPUT
-          exit 0
+        if ! EMAIL=$(git check-mailmap "$AUTHOR_NAME" 2>/dev/null); then
+          echo "GitHub handle $AUTHOR_NAME not found in mailmap" >&2
+          exit 1
         fi
 
-        # Extract email and name from canonical form
-        CANONICAL_EMAIL=$(echo "$CANONICAL" | grep -o '<.*>' | tr -d '<>')
-        CANONICAL_NAME=$(echo "$CANONICAL" | sed 's/ <.*>//')
-
-        echo "email=$CANONICAL_EMAIL" >> $GITHUB_OUTPUT
-        echo "name=$CANONICAL_NAME" >> $GITHUB_OUTPUT
+        echo "email=$EMAIL" >> $GITHUB_OUTPUT
+        echo "name=$AUTHOR_NAME" >> $GITHUB_OUTPUT
 
     - name: Lookup by email
       if: inputs.step == 'start'

.mailmap

@@ -1,35 +1,15 @@
-Alban Dumouilla <alban@dust.tt>
-Alban Dumouilla <alban@dust.tt> <alban.dumouilla@gmail.com>
-Alexandre Pinot <alexandre@dust.tt>
-Alexandre Pinot <alexandre@dust.tt> <32997243+pinotalexandre@users.noreply.github.com>
-Aubin Tchoi <aubin@dust.tt>
-Aubin Tchoi <aubin@dust.tt> <60398825+aubin-tchoi@users.noreply.github.com>
-Aubin Tchoi <aubin@dust.tt> <aubin.tchoi@gmail.com>
-Daphné Popin <daph@dust.tt>
-Daphné Popin <daph@dust.tt> <daphne.popin@gmail.com>
-Daphné Popin <daph@dust.tt> <PopDaph@users.noreply.github.com>
-Edouard Wautier <ed@dust.tt>
-Edouard Wautier <ed@dust.tt> <4435185+Duncid@users.noreply.github.com>
-Flavien David <flavien@dust.tt>
-Flavien David <flavien@dust.tt> <flavien.david74@gmail.com>
-Gabriel Hubert <gabriel@dust.tt>
-Gabriel Hubert <gabriel@dust.tt> <gabriel.hubert@gmail.com>
-Henry Fontanier <henry@dust.tt>
-Henry Fontanier <henry@dust.tt> <h.fontanier@gmail.com>
-Jules Belveze <jules@dust.tt>
-Jules Belveze <jules@dust.tt> <32683010+JulesBelveze@users.noreply.github.com>
-Jules Belveze <jules@dust.tt> <jules.belveze@hotmail.fr>
-Lucas Massemin <lucas@dust.tt>
-Lucas Massemin <lucas@dust.tt> <lucasmassemin@gmail.com>
-Pauline Pham <pauline@dust.tt>
-Pauline Pham <pauline@dust.tt> <33726902+Yutcam@users.noreply.github.com>
-Philippe Rolet <pr@dust.tt>
-Philippe Rolet <pr@dust.tt> <philipperolet@gmail.com>
-Sebastien Flory <seb@dust.tt>
-Sebastien Flory <seb@dust.tt> <sflory@gmail.com>
-Stanislas Polu <spolu@dust.tt>
-Stanislas Polu <spolu@dust.tt> <spolu@proton.me>
-Thibault Martin <thibault@dust.tt>
-Thibault Martin <thibault@dust.tt> <168569391+thib-martin@users.noreply.github.com>
-Thomas Draier <thomas@dust.tt>
-Thomas Draier <thomas@dust.tt> <thomas.draier@gmail.com>
+JulesBelveze jules@dust.tt
+pinotalexandre alexandre@dust.tt
+aubin-tchoi aubin@dust.tt
+PopDaph daph@dust.tt
+Duncid ed@dust.tt
+flavien flavien@dust.tt
+gabriel gabriel@dust.tt
+henry henry@dust.tt
+lucasmassemin lucas@dust.tt
+Yutcam pauline@dust.tt
+philipperolet pr@dust.tt
+sflory seb@dust.tt
+spolu spolu@dust.tt
+thib-martin thibault@dust.tt
+thomas thomas@dust.tt