[CI] Remove gcc 4.2 bots

We don't support that version anymore.
diff --git a/.circleci/config.yml b/.circleci/config.yml
index 6a01e54..ca73f81 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -22,29 +22,6 @@
       - run: make -j4
       - run: make check || .ci/fail.sh
 
-  macos-llvm-gcc-4.2:
-    macos:
-      xcode: "8.3.3"
-    steps:
-      - checkout
-      - run: HOMEBREW_NO_AUTO_UPDATE=1 brew install wget pkg-config libtool ragel freetype glib cairo
-      - run: wget https://packages.macports.org/llvm-gcc42/llvm-gcc42-2336.11_3+universal.darwin_15.i386-x86_64.tbz2 && tar zxvf llvm-gcc42-2336.11_3+universal.darwin_15.i386-x86_64.tbz2
-      - run: CC=$PWD/opt/local/bin/llvm-gcc-4.2 CXX=$PWD/opt/local/bin/llvm-g++-4.2 ./autogen.sh --with-freetype --with-glib --with-gobject --with-cairo
-      # Ignoring assembler complains, https://stackoverflow.com/a/39867021
-      - run: make 2>&1 | grep -v -e '^/var/folders/*' -e '^[[:space:]]*\.section' -e '^[[:space:]]*\^[[:space:]]*~*'
-      - run: make check || .ci/fail.sh
-
-  macos-notest-apple-gcc-i686-4.2:
-    macos:
-      xcode: "8.3.3"
-    steps:
-      - checkout
-      - run: HOMEBREW_NO_AUTO_UPDATE=1 brew install wget pkg-config libtool ragel
-      - run: wget https://packages.macports.org/apple-gcc42/apple-gcc42-5666.3_15+universal.darwin_15.i386-x86_64.tbz2 && tar zxvf apple-gcc42-5666.3_15+universal.darwin_15.i386-x86_64.tbz2
-      - run: CPP=$PWD/opt/local/bin/i686-apple-darwin15-cpp-apple-4.2.1 CC=$PWD/opt/local/bin/i686-apple-darwin15-gcc-apple-4.2.1 CXX=$PWD/opt/local/bin/i686-apple-darwin15-g++-apple-4.2.1 ./autogen.sh
-      # Ignoring assembler complains, https://stackoverflow.com/a/39867021
-      - run: make 2>&1 | grep -v -e '^/var/folders/*' -e '^[[:space:]]*\.section' -e '^[[:space:]]*\^[[:space:]]*~*'
-
   macos-notest-ios:
     macos:
       xcode: "10.0.0"
@@ -322,8 +299,6 @@
       # macOS
       - macos-10.12.6-aat-fonts
       - macos-10.13.6-aat-fonts
-      - macos-llvm-gcc-4.2
-      - macos-notest-apple-gcc-i686-4.2
       - macos-notest-ios
 
       # both autotools and cmake