Claude Code GH Action fails with exception.

**Describe the bug**
Claude Code GitHub Action crashes due to missing exception handling and just terminates without completion.

**To Reproduce**
Steps to reproduce the behavior:

```
Fetching issue comment 3061519462
Successfully fetched as issue comment
GET /repos/shader-slang/slang/branches/claude%2Fissue-7723-20250711_093411 - 404 with id 07C0:2AF3A7:297C16E:53D270B:6870DB2D in 98ms
Branch claude/issue-7723-20250711_093411 does not exist remotely
Branch claude/issue-7723-20250711_093411 does not exist remotely, no branch link will be added
GET /repos/shader-slang/slang/compare/master...claude%2Fissue-7723-20250711_093411 - 404 with id 07C0:2AF3A7:297C1EC:53D280C:6870DB2D in 83ms
Error checking for changes in branch: 11 | /**
12 | * Response object if a response was received
13 | */
14 | response;
15 | constructor(message, statusCode, options) {
16 | super(message);
^
HttpError: Not Found - https://docs.github.com/rest/commits/commits#compare-two-commits
status: 404,
request: {
method: "GET",
url: "https://api.github.com/repos/shader-slang/slang/compare/master...claude%2Fissue-7723-20250711_093411",
headers: [Object ...],
request: [Object ...],
},
response: {
url: "https://api.github.com/repos/shader-slang/slang/compare/master...claude%2Fissue-7723-20250711_093411",
status: 404,
headers: [Object ...],
data: [Object ...],
},

at new RequestError (/home/runner/work/_actions/anthropics/claude-code-action/beta/node_modules/@octokit/rest/node_modules/@octokit/core/node_modules/@octokit/request-error/dist-src/index.js:16:5)
at fetchWrapper (/home/runner/work/_actions/anthropics/claude-code-action/beta/node_modules/@octokit/rest/node_modules/@octokit/core/node_modules/@octokit/request/dist-bundle/index.js:122:11)

```

**Expected behavior**
Should run to completion.

**Screenshots**
N.A.

**Workflow yml file**
Similar to reference workflow [Workflow](https://github.com/shader-slang/slang/blob/master/.github/workflows/claude.yml)
**API Provider**

[ ] Anthropic First-Party API (default)
[x] AWS Bedrock
[ ] GCP Vertex

**Additional context**
Add any other context about the problem here.