yes you have repeated the same identical layers, infact you have used the same layer twice. They will have the same weights because at the end of the day they are the same thing.
However:
self.linear = nn.Linear(1, 1)
self.linear1 = nn.Linear(1, 1)
...
 def forward(self, x):
     output = self.linear(x)
     output = self.linear1(output)  # re-using self.linear
     return output

linear1 and linear will have different weights. Even though you used the same nn.Linear(1, 1)