docs: async pagination examples use incompatible thenRun lambda

[abhinavkr26104]

Description

The asynchronous pagination examples in README.md pass a page-consuming lambda to CompletableFuture.thenRun, but thenRun accepts a zero-argument Runnable and does not provide the completed page.

Reproduction

Copy any of the async pagination examples around README.md lines 1346, 1351, or 1369 into a Java source file:

pageFuture.thenRun(page -> page.autoPager().subscribe(job -> {
    System.out.println(job);
}));

Compile the example with the SDK dependencies.

Expected behavior

The documentation should use a CompletableFuture method whose callback receives the completed page.

Actual behavior

The examples fail to compile because the lambda has one parameter while thenRun expects a no-argument Runnable.

Why this matters

Users following the documented async pagination examples encounter a compile error before making any API request.

Suggested fix

Replace thenRun with thenAccept in all three async pagination examples.