dockerfiles: Remove 'MAINTAINER' entry in debian-tricore-cross.docker

AMSAT closed its email service [*] so my personal email
address is now defunct. Remove it to avoid bouncing emails.

[*] https://forum.amsat-dl.org/index.php?thread/4581-amsat-mail-alias-service-to-end-august-1-2024/

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

tests/docker/dockerfiles/debian-tricore-cross.docker

@@ -11,8 +11,6 @@
 #
 FROM docker.io/library/debian:11-slim
 
-MAINTAINER Philippe Mathieu-Daudé <f4bug@amsat.org>
-
 RUN apt update && \
     DEBIAN_FRONTEND=noninteractive apt install -yy eatmydata && \
     DEBIAN_FRONTEND=noninteractive eatmydata apt install -yy \