[.github] - refactor: switch from mailmap to custom authors file for …

…slack notifications (#8973)

- Removed mailmap lookup and replaced it with a check against a custom `.authors` file
 - Adapted Slack notification action to fetch author email from the new `.authors` file instead of `.mailmap`

[.authors] - feature: add custom .authors file with contributor emails

 - Introduced a `.authors` file to maintain a list of contributor emails for the repository

[misc] - refactor: remove obsolete .mailmap file

 - Deleted the `.mailmap` file as the repository now uses a custom `.authors` file for email lookup

.authors

@@ -0,0 +1,16 @@
+JulesBelveze: [email protected]
+pinotalexandre: [email protected]
+aubin-tchoi: [email protected]
+PopDaph: [email protected]
+Duncid: [email protected]
+flvndvd: [email protected]
+gabriel: [email protected]
+fontanierh: [email protected]
+overmode: [email protected]
+Yutcam: [email protected]
+philipperolet: [email protected]
+Fraggle: [email protected]
+spolu: [email protected]
+thib-martin: [email protected]
+tdraier: [email protected]
+albandum: [email protected]

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

@@ -36,13 +36,11 @@ runs:
       run: |
         AUTHOR_NAME="${{ github.actor }}"
 
-        if ! EMAIL=$(git check-mailmap "$AUTHOR_NAME" 2>/dev/null); then
-          echo "GitHub handle $AUTHOR_NAME not found in mailmap" >&2
+        if ! EMAIL=$(grep "^$RAW_AUTHOR: " .authors | cut -d' ' -f2); then
+          echo "GitHub handle $RAW_AUTHOR not found in authors file" >&2
           exit 1
         fi
-
         echo "email=$EMAIL" >> $GITHUB_OUTPUT
-        echo "name=$AUTHOR_NAME" >> $GITHUB_OUTPUT
 
     - name: Lookup by email
       if: inputs.step == 'start'