fix: comply with camelCase naming convention for coverage fixture

Rename _coverageCollector to coverageCollector to satisfy the
@typescript-eslint/naming-convention rule, and suppress the rule
for the Istanbul __coverage__ global which cannot be renamed.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: gustavolira

src/playwright/fixtures/test.ts

@@ -10,7 +10,7 @@ type RHDHDeploymentTestFixtures = {
   rhdh: RHDHDeployment;
   uiHelper: UIhelper;
   loginHelper: LoginHelper;
-  _coverageCollector: void;
+  coverageCollector: void;
 };
 
 type RHDHDeploymentWorkerFixtures = {
@@ -63,7 +63,7 @@ const baseTest = base.extend<
     },
     { scope: "test" },
   ] as const,
-  _coverageCollector: [
+  coverageCollector: [
     async ({ page }, use, testInfo) => {
       await use();
       if (process.env.E2E_COLLECT_COVERAGE !== "1") return;
@@ -72,6 +72,7 @@ const baseTest = base.extend<
           () =>
             (
               globalThis as unknown as {
+                // eslint-disable-next-line @typescript-eslint/naming-convention
                 __coverage__?: Record<string, unknown>;
               }
             ).__coverage__,