Merge bitcoin/bitcoin#23744: build, qt: Drop support for i686-linux-android host

66a20a54a2 build, qt: Drop support for `i686-linux-android` host (Hennadii Stepanov)

Pull request description:

  There are no reasons to keep support for `i686-linux-android` host, which is actually broken in master (50c502f54a), and this fact has been unnoticed for months :)

  https://github.com/bitcoin/bitcoin/pull/23675#issuecomment-986206434:
  > I'm surprised `i686-linux-android` ABI is still supported. I would love to drop it...

  https://github.com/bitcoin/bitcoin/pull/23675#issuecomment-991340132
  > What is `i686-linux-android`? 32-bit x86 android? is that really a thing?

ACKs for top commit:
  prusnak:
    utACK 66a20a54a2

Tree-SHA512: 211f794de2fc569f0ade2a4da805b8bfd4ce2ab0930c5d427acc4f5d015fcdc4911f02fc64f6401197f7641aed79944a9594be80c817547be3269cdd721cf79b

configure.ac

@@ -776,10 +776,7 @@ case $host in
         *armv7a*)
           ANDROID_ARCH=armeabi-v7a
           ;;
-        *i686*)
-          ANDROID_ARCH=i686
-          ;;
-        *) AC_MSG_ERROR([Could not determine Android arch]) ;;
+        *) AC_MSG_ERROR([Could not determine Android arch, or it is unsupported]) ;;
       esac
      ;;
    *linux*)

depends/README.md

@@ -38,7 +38,6 @@ Common `host-platform-triplet`s for cross compilation are:
 - `s390x-linux-gnu` for Linux S390X
 - `armv7a-linux-android` for Android ARM 32 bit
 - `aarch64-linux-android` for Android ARM 64 bit
-- `i686-linux-android` for Android x86 32 bit
 - `x86_64-linux-android` for Android x86 64 bit
 
 The paths are automatically configured and no other options are needed unless targeting [Android](../doc/build-android.md).

depends/packages/qt.mk

@@ -181,7 +181,6 @@ $(package)_config_opts_android += -no-feature-vulkan
 $(package)_config_opts_aarch64_android += -android-arch arm64-v8a
 $(package)_config_opts_armv7a_android += -android-arch armeabi-v7a
 $(package)_config_opts_x86_64_android += -android-arch x86_64
-$(package)_config_opts_i686_android += -android-arch i686
 endef
 
 define $(package)_fetch_cmds