fix: widen fs.file-max sysctl from int32 to int64 (#8640)

Sets the right data type(int64) for fs.file-max sysctl parameter, matching the Linux kernel default that customers already see at runtime. Also matches the documentation here: https://learn.microsoft.com/en-us/azure/aks/custom-node-configuration?tabs=linux-node-pools

Author: fcher

aks-node-controller/pkg/gen/aksnodeconfig/v1/custom_linux_os_config.pb.go

@@ -49,7 +49,7 @@ message SysctlConfig {
   optional int32 net_netfilter_nf_conntrack_max = 19;
   optional int32 net_netfilter_nf_conntrack_buckets = 20;
   optional int32 fs_inotify_max_user_watches = 21;
-  optional int32 fs_file_max = 22;
+  optional int64 fs_file_max = 22;
   optional int32 fs_aio_max_nr = 23;
   optional int32 fs_nr_open = 24;
   optional int32 kernel_threads_max = 25;

aks-node-controller/proto/aksnodeconfig/v1/custom_linux_os_config.proto

@@ -800,7 +800,7 @@ type SysctlConfig struct {
 	NetNetfilterNfConntrackMax     *int32 `json:"netNetfilterNfConntrackMax,omitempty"`
 	NetNetfilterNfConntrackBuckets *int32 `json:"netNetfilterNfConntrackBuckets,omitempty"`
 	FsInotifyMaxUserWatches        *int32 `json:"fsInotifyMaxUserWatches,omitempty"`
-	FsFileMax                      *int32 `json:"fsFileMax,omitempty"`
+	FsFileMax                      *int64 `json:"fsFileMax,omitempty"`
 	FsAioMaxNr                     *int32 `json:"fsAioMaxNr,omitempty"`
 	FsNrOpen                       *int32 `json:"fsNrOpen,omitempty"`
 	KernelThreadsMax               *int32 `json:"kernelThreadsMax,omitempty"`