Remove obsolete ruby-oci8 2.0.3 TIMESTAMP patch

The oci8_patches.rb file patched a fractional seconds bug that only
activated for ruby-oci8 2.0.3. Since the project requires ~> 2.1
(and the fix was included in 2.0.4), this patch has been dead code
for years. Also bump the runtime version check and update the README
to reflect the 2.1 minimum.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: yahonda

README.md

@@ -135,7 +135,7 @@ or include gem in Gemfile if using bundler.
 
 In addition install either ruby-oci8 (for MRI/YARV) or copy Oracle JDBC driver to $JRUBY_HOME/lib (for JRuby).
 
-If you are using MRI Ruby implementation then you need to install ruby-oci8 gem (version 2.0.x or 2.1.x)
+If you are using MRI Ruby implementation then you need to install ruby-oci8 gem (version 2.1 or higher)
 as well as Oracle client, e.g. [Oracle Instant Client](http://www.oracle.com/technetwork/database/features/instant-client/index-097480.html).
 
 If you are using JRuby then you need to download latest [Oracle JDBC driver](http://www.oracle.com/technetwork/database/enterprise-edition/jdbc-112010-090769.html) - either ojdbc7.jar for Java 8 and 7, ojdbc6.jar for Java 6, 7, 8 or ojdbc5.jar for Java 5. You can refer [the support matrix](http://www.oracle.com/technetwork/database/enterprise-edition/jdbc-faq-090281.html#01_03) for details.

lib/plsql/oci8_patches.rb

@@ -14,10 +14,8 @@
   raise LoadError, "ERROR: ruby-plsql could not load ruby-oci8 library. #{msg}"
 end
 
-require "plsql/oci8_patches"
-
 # check ruby-oci8 version
-required_oci8_version = [2, 0, 3]
+required_oci8_version = [2, 1, 0]
 oci8_version_ints = OCI8::VERSION.scan(/\d+/).map { |s| s.to_i }
 if (oci8_version_ints <=> required_oci8_version) < 0
   raise LoadError, "ERROR: ruby-oci8 version #{OCI8::VERSION} is too old. Please install ruby-oci8 version #{required_oci8_version.join('.')} or later."