doc: update sea example by fixing wrong code example

The SEA configuration defines the output binary as `sea`, but the
signing and run steps still referenced `hello`. Update the example
to use `sea` consistently so the commands match the generated
binary.

Signed-off-by: Maxence Robinet <107369283+saint-james-fr@users.noreply.github.com>
PR-URL: #64025
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>

Author: saint-james-fr

doc/api/single-executable-applications.md

@@ -134,7 +134,7 @@ tool, [postject][]:
    * On macOS:
 
    ```bash
-   codesign --sign - hello
+   codesign --sign - sea
    ```
 
    * On Windows (optional):
@@ -143,22 +143,22 @@ tool, [postject][]:
    binary would still be runnable.
 
    ```powershell
-   signtool sign /fd SHA256 hello.exe
+   signtool sign /fd SHA256 sea.exe
    ```
 
 8. Run the binary:
 
    * On systems other than Windows
 
    ```console
-   $ ./hello world
+   $ ./sea world
    Hello, world!
    ```
 
    * On Windows
 
    ```console
-   $ .\hello.exe world
+   $ .\sea.exe world
    Hello, world!
    ```