Fix Drone pushing commits with wrong author info (#21450)

I don't know how to test this so I'll explain my thought process:

After a discussion with @techknowlogick in
https://github.com/go-gitea/gitea/commit/cda2c38f4a61ef7f448be3efab5420d9974c8474
I saw the CI config has this block:

https://github.com/go-gitea/gitea/blob/cda2c38f4a61ef7f448be3efab5420d9974c8474/.drone.yml#L618-L630

I don't know much about Drone but after looking at
[appleboy/drone-git-push](https://github.com/appleboy/drone-git-push)'s
source code, I think each setting becomes an environment variable (e.g.
`remote` to `PLUGIN_REMOTE`, `commit_message` to `PLUGIN_COMMIT_MESSAGE`
etc...). Take a look at the code block loading the author info:

https://github.com/appleboy/drone-git-push/blob/a69878c00665277c53fb38d6c5980221cb687935/main.go#L32-L42

Two environment variables are listed for each setting. This PR forces
both to have the same value.

Signed-off-by: Yarden Shoham <hrsi88@gmail.com>

.drone.yml

@@ -626,6 +626,8 @@ steps:
       commit_message: "[skip ci] Updated translations via Crowdin"
       remote: "git@github.com:go-gitea/gitea.git"
     environment:
+      DRONE_COMMIT_AUTHOR_EMAIL: "teabot@gitea.io"
+      DRONE_COMMIT_AUTHOR: GiteaBot
       GIT_PUSH_SSH_KEY:
         from_secret: git_push_ssh_key
 
@@ -670,12 +672,14 @@ steps:
     pull: always
     settings:
       author_email: "teabot@gitea.io"
-      author_name: GiteaBot
+      author_name: "GiteaBot"
       branch: main
       commit: true
-      commit_message: "[skip ci] Updated licenses and gitignores "
+      commit_message: "[skip ci] Updated licenses and gitignores"
       remote: "git@github.com:go-gitea/gitea.git"
     environment:
+      DRONE_COMMIT_AUTHOR_EMAIL: "teabot@gitea.io"
+      DRONE_COMMIT_AUTHOR: "GiteaBot"
       GIT_PUSH_SSH_KEY:
         from_secret: git_push_ssh_key