ICU-22310 Update configure files from configure.ac using autoreconf.

icu4c/source/configure

@@ -733,9 +733,6 @@ UNICODE_VERSION
 LIB_VERSION_MAJOR
 LIB_VERSION
 VERSION
-ICU_ECHO_T
-ICU_ECHO_C
-ICU_ECHO_N
 PACKAGE
 target_alias
 host_alias
@@ -2576,24 +2573,6 @@ export PYTHONDONTWRITEBYTECODE
 PACKAGE="icu"
 
 
-# Use custom echo test for newline option
-# Current autoconf (2.65) gives incorrect echo newline option
-# for icu-config
-# This may be removed later - mow (June 17, 2010)
-ICU_ECHO_C= ICU_ECHO_N= ICU_ECHO_T=
-case `/bin/sh -c "echo -n x"` in
--n*)
-  case `/bin/sh -c "echo 'x\c'"` in
-  *c*) ICU_ECHO_T=' ';;     # ECHO_T is single tab character.
-  *)   ICU_ECHO_C='\c';;
-  esac;;
-*)
-  ICU_ECHO_N='-n';;
-esac
-
-
-
-
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for ICU version numbers" >&5
 $as_echo_n "checking for ICU version numbers... " >&6; }