Add arm64 standard runners pricing (#59542)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: kyanny

data/reusables/billing/actions-standard-runner-prices.md

@@ -1,6 +1,8 @@
-| Operating system                     | Billing SKU  | Per-minute rate (USD) |
-| ------------------------------------ | -------------| ----------------------|
-| Linux 1-core                         | `linux_slim` | $0.002                |
-| Linux 2-core                         | `linux`      | $0.006                |
-| Windows 2-core                       | `windows`    | $0.010                |
-| macOS 3-core or 4-core (M1 or Intel) | `macos`      | $0.062                |
+| Operating system                     | Billing SKU           | Per-minute rate (USD) |
+| ------------------------------------ | --------------------- | --------------------- |
+| Linux 1-core (x64)                   | `actions_linux_slim`  | $0.002                |
+| Linux 2-core (x64)                   | `actions_linux`       | $0.006                |
+| Linux 2-core (arm64)                 | `actions_linux_arm`   | $0.005                |
+| Windows 2-core (x64)                 | `actions_windows`     | $0.010                |
+| Windows 2-core (arm64)               | `actions_windows_arm` | $0.010                |
+| macOS 3-core or 4-core (M1 or Intel) | `actions_macos`       | $0.062                |