Add support for Debian Bookworm/PHP 8

bookworm_php8/Dockerfile-base

@@ -0,0 +1,36 @@
+FROM debian:bookworm
+LABEL maintainer="jan@dittberner.info"
+VOLUME /srv
+
+RUN apt-get update \
+    && DEBIAN_FRONTEND=noninteractive \
+    apt-get install -y --no-install-recommends \
+    ca-certificates \
+    dumb-init \
+    libnss-ldap \
+    nullmailer \
+    openssl \
+    php-mail-mime \
+    php-net-smtp \
+    php-net-socket \
+    php8.1 \
+    php8.1-curl \
+    php8.1-fpm \
+    php8.1-fpm \
+    php8.1-gd \
+    php8.1-imagick \
+    php8.1-imap \
+    php8.1-intl \
+    php8.1-mbstring \
+    php8.1-opcache \
+    php8.1-pspell \
+    php8.1-sqlite3 \
+    php8.1-zip \
+    psmisc \
+    && apt-get clean \
+    && rm -rf /var/lib/apt/lists/*.*
+
+# broken as of Tue Nov 15 07:42:37 CET 2022
+# php-mail https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1000653
+
+ADD --chown=root:root nsswitch.conf libnss-ldap.conf /etc/