Add capabilities requirement to changelog (#8730)

CHANGELOG.md

@@ -43,6 +43,7 @@ Release channels have their own copy of this changelog:
 ### Validator
 
 #### Breaking
+* When XDP is enabled, the validator process requires the `CAP_NET_RAW`, `CAP_NET_ADMIN`, `CAP_BPF`, and `CAP_PERFMON` capabilities. These can be configured in the systemd service file by setting `CapabilityBoundingSet=CAP_NET_RAW CAP_NET_ADMIN CAP_BPF CAP_PERFMON` under the `[Service]` section or directly on the binary with the command `sudo setcap cap_net_raw,cap_net_admin,cap_bpf,cap_perfmon=p <path/to/agave-validator>` (this command must be run each time the binary is replaced)
 * Require increased `memlock` limits - recommended setting is `LimitMEMLOCK=2000000000` in systemd service configuration. Lack of sufficient limit (on Linux) will cause startup error.
 * Remove deprecated arguments
   * `--accounts-index-memory-limit-mb`