refactor(github): build request headers once

GitHubApi built the accept and x-github-api-version pair inline at three request sites (tryList, request, tryGraphql). One private headers() method now returns the pair, and the raw media-type read passes its own accept. Nothing on the wire changes.

Author: Vivswan

src/github/api.ts

@@ -221,6 +221,10 @@ export class GitHubApi implements GitHubClient {
     });
   }
 
+  private headers(accept = "application/vnd.github+json"): Record<string, string> {
+    return { accept, "x-github-api-version": this.apiVersion };
+  }
+
   async tryRequest(
     method: string,
     path: string,
@@ -295,10 +299,7 @@ export class GitHubApi implements GitHubClient {
       url: path,
       per_page: options?.perPage ?? PAGE_SIZE,
       page: 1,
-      headers: {
-        accept: "application/vnd.github+json",
-        "x-github-api-version": this.apiVersion,
-      },
+      headers: this.headers(),
     } as unknown as Parameters<RequestInterface>[0];
     try {
       for await (const _page of this.octokit.paginate.iterator(request, firstPage)) {
@@ -357,10 +358,7 @@ export class GitHubApi implements GitHubClient {
       const response = await this.octokit.request({
         method,
         url: path,
-        headers: {
-          accept: options?.accept ?? "application/vnd.github+json",
-          "x-github-api-version": this.apiVersion,
-        },
+        headers: this.headers(options?.accept),
         // The body is the tree the scan inspected, so octokit never reshapes the payload and the wire carries exactly what was scanned.
         ...(payload === undefined ? {} : { data: secretScan.value.payload }),
       } as unknown as Parameters<InstanceType<typeof ActionOctokit>["request"]>[0]);
@@ -437,10 +435,7 @@ export class GitHubApi implements GitHubClient {
       response = (await this.octokit.request({
         method: "POST",
         url: "/graphql",
-        headers: {
-          accept: "application/vnd.github+json",
-          "x-github-api-version": this.apiVersion,
-        },
+        headers: this.headers(),
         // operationName makes the request self-describing on the wire (the mock dispatches on it).
         data: { query: op.query, operationName: op.name, variables: scan.value.payload },
       } as unknown as Parameters<InstanceType<typeof ActionOctokit>["request"]>[0])) as {