minor #33987 [CI] fix building local packages (nicolas-grekas)

This PR was merged into the 3.4 branch.

Discussion
----------

[CI] fix building local packages

| Q             | A
| ------------- | ---
| Branch?       | 3.4
| Bug fix?      | no
| New feature?  | no
| Deprecations? | no
| Tickets       | -
| License       | MIT
| Doc PR        | -

Commits
-------

b7b6942251 [CI] fix building local packages

.appveyor.yml

@@ -54,6 +54,8 @@ install:
     - php composer.phar self-update
     - copy /Y .github\composer-config.json %APPDATA%\Composer\config.json
     - php composer.phar global require --no-progress --no-scripts --no-plugins symfony/flex dev-master
+    - git config --global user.email ""
+    - git config --global user.name "Symfony"
     - php .github/build-packages.php "HEAD^" src\Symfony\Bridge\PhpUnit
     - IF %APPVEYOR_REPO_BRANCH%==master (SET COMPOSER_ROOT_VERSION=dev-master) ELSE (SET COMPOSER_ROOT_VERSION=%APPVEYOR_REPO_BRANCH%.x-dev)
     - php composer.phar config platform.php 5.5.9

.github/build-packages.php

@@ -47,7 +47,7 @@ foreach ($dirs as $k => $dir) {
     if (isset($preferredInstall[$package->name]) && 'source' === $preferredInstall[$package->name]) {
         passthru("cd $dir && tar -cf package.tar --exclude='package.tar' *");
     } else {
-        passthru("cd $dir && git init && git add . && git commit --author \"Symfony <>\" -m - && git archive -o package.tar HEAD && rm .git/ -Rf");
+        passthru("cd $dir && git init && git add . && git commit -q -m - && git archive -o package.tar HEAD && rm .git/ -Rf");
     }
 
     if (!isset($package->extra->{'branch-alias'}->{'dev-master'})) {

.travis.yml

@@ -212,6 +212,9 @@ install:
 
     - |
       # Create local composer packages for each patched components and reference them in composer.json files when cross-testing components
+      git config --global user.email ""
+      git config --global user.name "Symfony"
+
       if [[ ! $deps ]]; then
           php .github/build-packages.php HEAD^ src/Symfony/Bridge/PhpUnit
       else