Remove no-longer-usable hstore--1.0--1.1.sql update script.

Since commit 865f14a2d made "=>" unusable as an operator name,
it's been impossible either to install hstore 1.0 or to execute
this update script.  There's not much point in continuing
to ship it.

Discussion: https://postgr.es/m/653936.1597431032@sss.pgh.pa.us

contrib/hstore/Makefile

@@ -15,7 +15,7 @@ DATA = hstore--1.4.sql \
 	hstore--1.5--1.6.sql \
 	hstore--1.4--1.5.sql \
 	hstore--1.3--1.4.sql hstore--1.2--1.3.sql \
-	hstore--1.1--1.2.sql hstore--1.0--1.1.sql
+	hstore--1.1--1.2.sql
 PGFILEDESC = "hstore - key/value pair data type"
 
 HEADERS = hstore.h

contrib/hstore/hstore--1.0--1.1.sql

@@ -1,7 +0,0 @@
-/* contrib/hstore/hstore--1.0--1.1.sql */
-
--- complain if script is sourced in psql, rather than via ALTER EXTENSION
-\echo Use "ALTER EXTENSION hstore UPDATE TO '1.1'" to load this file. \quit
-
-ALTER EXTENSION hstore DROP OPERATOR => (text, text);
-DROP OPERATOR => (text, text);