Drop redundant require "spec_helper" from spec files

The project-level .rspec (added in rsim#294) sets `--require spec_helper`,
so each spec file's explicit `require "spec_helper"` is now redundant.
Remove the require line and the trailing blank line from all 11 spec
files under spec/plsql/.

Net change: -22 LOC. No behavior change. Full suite is green
(468 examples, 0 failures, 1 pre-existing pending).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: yahonda

spec/plsql/connection_spec.rb

@@ -1,7 +1,5 @@
 # encoding: utf-8
 
-require "spec_helper"
-
 RSpec.describe "Connection" do
 
   before(:all) do

spec/plsql/package_spec.rb

@@ -1,5 +1,3 @@
-require "spec_helper"
-
 RSpec.describe "Package" do
   before(:all) do
     plsql.connection = get_connection

spec/plsql/procedure_spec.rb

@@ -1,7 +1,5 @@
 # encoding: utf-8
 
-require "spec_helper"
-
 RSpec.describe "Parameter type mapping /" do
 
   shared_examples "Function with string parameters" do |datatype|

spec/plsql/schema_spec.rb

@@ -1,5 +1,3 @@
-require "spec_helper"
-
 RSpec.describe "Schema" do
 
   it "should create Schema object" do

spec/plsql/sequence_spec.rb

@@ -1,5 +1,3 @@
-require "spec_helper"
-
 RSpec.describe "Table" do
   before(:all) do
     plsql.connection = get_connection

spec/plsql/sql_statements_spec.rb

@@ -1,5 +1,3 @@
-require "spec_helper"
-
 RSpec.describe "SQL statements /" do
   before(:all) do
     plsql.connect! CONNECTION_PARAMS

spec/plsql/table_spec.rb

@@ -1,5 +1,3 @@
-require "spec_helper"
-
 RSpec.describe "Table" do
   before(:all) do
     plsql.connect! CONNECTION_PARAMS

spec/plsql/type_spec.rb

@@ -1,5 +1,3 @@
-require "spec_helper"
-
 RSpec.describe "Type" do
   before(:all) do
     plsql.connection = get_connection

spec/plsql/variable_spec.rb

@@ -1,7 +1,5 @@
 # encoding: utf-8
 
-require "spec_helper"
-
 RSpec.describe "Package variables /" do
 
   describe "String" do

spec/plsql/version_spec.rb

@@ -1,5 +1,3 @@
-require "spec_helper"
-
 RSpec.describe "Version" do
   it "should return ruby-plsql version" do
     expect(PLSQL::VERSION).to eq(File.read(File.dirname(__FILE__) + "/../../VERSION").chomp)