ci: Updates grape appraisals (#1006)

Fixes #1005

Author: arielvalentin

instrumentation/grape/Appraisals

@@ -4,26 +4,15 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 
-appraise 'grape-1.2' do
-  gem 'grape', '~> 1.2'
+appraise 'grape-1.x' do
+  gem 'rack', '~> 2.0'
+  gem 'grape', '~> 1.8'
 end
 
-appraise 'grape-1.3' do
-  gem 'grape', '~> 1.3'
+appraise 'grape-2.0.x' do
+  gem 'grape', '~> 2.0.0'
 end
 
-appraise 'grape-1.4' do
-  gem 'grape', '~> 1.4'
-end
-
-appraise 'grape-1.5' do
-  gem 'grape', '~> 1.5'
-end
-
-appraise 'grape-1.6' do
-  gem 'grape', '~> 1.6'
-end
-
-appraise 'grape-1.7' do
-  gem 'grape', '~> 1.7'
+appraise 'grape-latest' do
+  gem 'grape'
 end