Use Netty contributions from main branches (#2457)

The Netty contribs (codec-extras, codec-haproxy, socks-proxy) have been merged into their main branches with the following fixed PRs:

Rename Statics to InternalBufferUtils (Rename Statics to InternalBufferUtils netty/netty#12739)
Remove Charset constants from CharsetUtil (Remove Charset constants from CharsetUtil netty/netty#12741)

So, we can now point to the contribs main branches instead of their PR branches

.github/workflows/check_transport.yml

@@ -56,22 +56,16 @@ jobs:
           fetch-depth: 0 #needed by spotless
       - uses: actions/checkout@v3
         with:
-          # TODO temporary https://github.com/netty-contrib/codec-haproxy/pull/12
-          repository: pderop/codec-haproxy
+          repository: netty-contrib/codec-haproxy
           path: codec-haproxy
-          ref: adapt-to-netty-changes-for-charsetutil-statics
       - uses: actions/checkout@v3
         with:
-          # TODO temporary https://github.com/netty-contrib/codec-extras/pull/14
-          repository: pderop/codec-extras
+          repository: netty-contrib/codec-extras
           path: codec-extras
-          ref: adapt-to-netty-changes-for-charsetutil
       - uses: actions/checkout@v3
         with:
-          # TODO temporary https://github.com/netty-contrib/socks-proxy/pull/20
-          repository: pderop/socks-proxy
+          repository: netty-contrib/socks-proxy
           path: socks-proxy
-          ref: adapt-to-netty-changes-for-charsetutil
       - uses: gradle/wrapper-validation-action@v1
       - name: Set up JDK 17
         uses: actions/setup-java@v3