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

Since commit 865f14a 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

Author: tglsfdc

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