Upgrade baseline curl to 8.1.1 (#160)

* Upgrade baseline curl to 8.1.1

New curl version includes bugfixes, new options but mainly websocket
support which was long requested in curl impersonate. Upstream curl
reworked a lot of their http2 code which necessitated a lot of changes
on our side as well.

* Fix build on mac due to bad header priorities

On macos, clang gives priority to /usr/local/include
over locations specified with -isystem for some unknown reason. In turn
this causes clang to use the system's openssl, which conflicts with
curl-impersonate's boringssl headers.
To prevent that, disable curl's automatic conversion of -I flags to
-isystem.

* Upgrade zlib version

* Upgrade GitHub Mac runner to macos-12

* Upgrade nghttp2 version to 1.56.0

curl-8.1.1 uses an nghttp2 function that only exists in newer versions
of nghttp2.

firefox/Dockerfile.alpine

@@ -43,8 +43,8 @@ RUN tar xf ${NSS_VERSION}.tar.gz && \
     cd ${NSS_VERSION}/nss && \
     ./build.sh -o --disable-tests --static --python=python3
 
-ARG NGHTTP2_VERSION=nghttp2-1.46.0
-ARG NGHTTP2_URL=https://github.com/nghttp2/nghttp2/releases/download/v1.46.0/nghttp2-1.46.0.tar.bz2
+ARG NGHTTP2_VERSION=nghttp2-1.56.0
+ARG NGHTTP2_URL=https://github.com/nghttp2/nghttp2/releases/download/v1.56.0/nghttp2-1.56.0.tar.bz2
 
 # Download nghttp2 for HTTP/2.0 support.
 RUN curl -o ${NGHTTP2_VERSION}.tar.bz2 -L ${NGHTTP2_URL}
@@ -56,7 +56,7 @@ RUN cd ${NGHTTP2_VERSION} && \
     make && make install
 
 # Download curl.
-ARG CURL_VERSION=curl-7.84.0
+ARG CURL_VERSION=curl-8.1.1
 RUN curl -o ${CURL_VERSION}.tar.xz https://curl.se/download/${CURL_VERSION}.tar.xz
 RUN tar xf ${CURL_VERSION}.tar.xz