F 修复执行发布前任务可能出现response timeout的问题

BUG原因：`_get_channel()` 这里没有考虑到应用环境变量命令长度问题，当命令在目标机执行时被截断时就会出问题，我参照 `exec_command()` 让 `_get_channel()` 这里也用一样的方式（`put_file_by_fl()`），就解决这个问题了。

另外`send()` 都调整成了 `sendall()` 防止极端情况下命令字符没有被全部发送出去而出问题。

有人曾反映过这个问题：https://github.com/openspug/spug/issues/455

----

相关的资料：

https://unix.stackexchange.com/questions/643777/is-there-any-limit-on-line-length-when-pasting-to-a-terminal-in-linux

https://stackoverflow.com/questions/18015137/linux-terminal-input-reading-user-input-from-terminal-truncating-lines-at-4095

https://github.com/torvalds/linux/blob/v5.11/drivers/tty/n_tty.c#L1681

spug_api/libs/ssh.py

@@ -31,7 +31,7 @@ class SSH:
         self.sftp = None
         self.exec_file = None
         self.eof = 'Spug EOF 2108111926'
-        self.default_env = self._make_env_command(default_env)
+        self.default_env = default_env
         self.regex = re.compile(r'Spug EOF 2108111926 (-?\d+)[\r\n]?')
         self.arguments = {
             'hostname': hostname,
@@ -83,7 +83,7 @@ class SSH:
     def exec_command(self, command, environment=None):
         channel = self._get_channel()
         command = self._handle_command(command, environment)
-        channel.send(command)
+        channel.sendall(command)
         out, exit_code = '', -1
         for line in self.stdout:
             match = self.regex.search(line)
@@ -112,7 +112,7 @@ class SSH:
     def exec_command_with_stream(self, command, environment=None):
         channel = self._get_channel()
         command = self._handle_command(command, environment)
-        channel.send(command)
+        channel.sendall(command)
         exit_code, line = -1, ''
         while True:
             line = self._decode(channel.recv(8196))
@@ -153,14 +153,14 @@ class SSH:
         counter = 0
         self.channel = self.client.invoke_shell()
         command = 'set +o history\nset +o zle\nset -o no_nomatch\nexport PS1= && stty -echo\n'
-        if self.default_env:
-            command += f'{self.default_env}\n'
-        command += f'echo {self.eof} $?\n'
-        self.channel.send(command.encode())
+        command = self._handle_command(command, self.default_env)
+        self.channel.sendall(command)
+        out = line = ''
         while True:
             if self.channel.recv_ready():
                 line = self._decode(self.channel.recv(8196))
-                if self.regex.search(line):
+                out += line
+                if self.regex.search(out):
                     self.stdout = self.channel.makefile('r')
                     break
             elif counter >= 100: