Duo Chat: Use "Action Input" not "ActionInput" in example

* I observed that Claude 2 still returns "Action Input" most of the time
  because that is what we tell it to return in the system prompt. But
  when I started working on Claude 3, I noticed that it was following
  this example and returning "ActionInput" instead. This broke our chain
  of thoguht parsing, which has a regex that matches on "Action Input"
  (with a space)
* This text without a space was added here: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/146634
* MR where Claude 3 work is happening: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/148223

ee/lib/gitlab/llm/chain/tools/ci_editor_assistant/executor.rb

@@ -23,7 +23,7 @@ class Executor < Tool
                 Thought: You have asked a question related to deployment of an application or CI/CD pipelines.
                   "CiEditorAssistant" tool can assist with this kind of questions.
                 Action: CiEditorAssistant
-                ActionInput: Please create a deployment configuration for a node.js application.
+                Action Input: Please create a deployment configuration for a node.js application.
               PROMPT
 
             PROVIDER_PROMPT_CLASSES = {

ee/lib/gitlab/llm/chain/tools/epic_reader/executor.rb

@@ -23,7 +23,7 @@ class Executor < EpicIdentifier::Executor
                   The question is about an epic, so you need to use "EpicReader" tool.
                   Based on this information you can present final answer.
                 Action: EpicReader
-                ActionInput: Please identify the author of &123 epic.
+                Action Input: Please identify the author of &123 epic.
               PROMPT
 
             PROVIDER_PROMPT_CLASSES = {

ee/lib/gitlab/llm/chain/tools/gitlab_documentation/executor.rb

@@ -22,7 +22,7 @@ class Executor < Tool
                 Thought: Question is about inner working of GitLab. "GitlabDocumentation" tool is the right one for
                   the job.
                 Action: GitlabDocumentation
-                ActionInput: How do I set up a new project?
+                Action Input: How do I set up a new project?
               PROMPT
 
             def perform(&_block)

ee/lib/gitlab/llm/chain/tools/issue_reader/executor.rb

@@ -24,7 +24,7 @@ class Executor < IssueIdentifier::Executor
                   Question is about the content of an issue, so you need to use "IssueReader" tool to retrieve and read issue.
                   Based on this information you can present final answer about issue.
                 Action: IssueReader
-                ActionInput: Please identify the author of #123 issue
+                Action Input: Please identify the author of #123 issue
               PROMPT
 
             PROVIDER_PROMPT_CLASSES = {