ARROW-8325: [R][CI] Stop including boost in R windows bundle

Closes #6822 from nealrichardson/rm-boost-again

Authored-by: Neal Richardson <neal.p.richardson@gmail.com>
Signed-off-by: Sutou Kouhei <kou@clear-code.com>

ci/scripts/r_windows_build.sh

@@ -81,8 +81,8 @@ mv mingw64/lib/*.a $DST_DIR/lib-4.9.3/x64
 mv mingw32/lib/*.a $DST_DIR/lib-4.9.3/i386
 
 # These are from https://dl.bintray.com/rtools/backports/
-cp $MSYS_LIB_DIR/mingw64/lib/lib{thrift,snappy,boost*}.a $DST_DIR/lib-4.9.3/x64
-cp $MSYS_LIB_DIR/mingw32/lib/lib{thrift,snappy,boost*}.a $DST_DIR/lib-4.9.3/i386
+cp $MSYS_LIB_DIR/mingw64/lib/lib{thrift,snappy}.a $DST_DIR/lib-4.9.3/x64
+cp $MSYS_LIB_DIR/mingw32/lib/lib{thrift,snappy}.a $DST_DIR/lib-4.9.3/i386
 
 # These are from https://dl.bintray.com/rtools/mingw{32,64}/
 cp $MSYS_LIB_DIR/mingw64/lib/lib{zstd,lz4,crypto}.a $DST_DIR/lib/x64