apache2 proxy and rewrite setup

In the build environment of my company, we are not allowed to access https://github.com directly, but only via a mirror https://mycompany.corp/github-proxy/mirror/. I would like to rewrite requests to github such that the mirror is used. I was tying to setup apache2 with mod_rewrite and mod_proxy as described here https://stackoverflow.com/a/35371232/9759769, but didn't manage to setup the rewrite rules correctly.

When I use curl to request github, the proxy is working but the url is not rewritten.

Here is my current docker configuration:

Dockerfile:

FROM ubuntu:22.04

RUN set -ex; \
    \
    apt-get clean; \
    apt-get update; \
    apt-get install -y --no-install-recommends \
      wget \
      curl \
      git \
      vim \
      ca-certificates \
      apache2; \
    rm -r /var/lib/apt/lists/*;

ADD forward_proxy.conf /etc/apache2/sites-available/
ADD proxy.conf /etc/apache2/mods-available/

RUN set -ex; \
    a2enmod proxy proxy_http proxy_connect rewrite ssl; \
    a2ensite forward_proxy.conf; \
    a2dissite 000-default.conf;

RUN apache2ctl configtest


ENV HTTP_PROXY="http://localhost:80"
ENV HTTPS_PROXY="http://localhost:80"

forward_proxy.conf:

<VirtualHost *:80>
RewriteEngine on

RewriteRule https://github.com/(.*) https://mycompany.corp/github-proxy/mirror/$1" [R,L]

SSLProxyEngine on

ProxyRequests on
AllowCONNECT 80 443
ProxyPreserveHost off


ErrorLog /var/log/apache2/forward_proxy.error.log
CustomLog /var/log/apache2/forward_proxy.access.log common
</VirtualHost>

proxy.conf:

<IfModule mod_proxy.c>

    # If you want to use apache2 as a forward proxy, uncomment the
    # 'ProxyRequests On' line and the <Proxy *> block below.
    # WARNING: Be careful to restrict access inside the <Proxy *> block.
    # Open proxy servers are dangerous both to your network and to the
    # Internet at large.
    #
    # If you only want to use apache2 as a reverse proxy/gateway in
    # front of some web application server, you DON'T need
    # 'ProxyRequests On'.

    ProxyRequests On
    <Proxy *>
       AddDefaultCharset off
       Require local
    </Proxy>

    # Enable/disable the handling of HTTP/1.1 "Via:" headers.
    # ("Full" adds the server version; "Block" removes all outgoing Via: headers)
    # Set to one of: Off | On | Full | Block
    #ProxyVia Off

</IfModule>