chore: remove repetitive words

network-upgrades/retrospectives/london.md

@@ -105,7 +105,7 @@ Solution: Do a `debug.setHead{X-1)` to jump to before the fork. This internally
 
 ##### Syncing in the presence of a wrong higher-td chain
 
-You are syncing a `geth`-node,  and a fork has occurred at block `X`. Since the fork has already happened, and the erroneous chain has higher TD, you will most likely wind up on the 'wrong' side of the chain, with a pivot block `X+M`. If this happens, you _do not have_ any state for blocks `<X+M`, so you _cannot_ do `debug.setHead` to to resolve the situation. 
+You are syncing a `geth`-node,  and a fork has occurred at block `X`. Since the fork has already happened, and the erroneous chain has higher TD, you will most likely wind up on the 'wrong' side of the chain, with a pivot block `X+M`. If this happens, you _do not have_ any state for blocks `<X+M`, so you _cannot_ do `debug.setHead` to resolve the situation. 
 
 In this case, a resync is required. However, you need to prevent geth from winding up on the wrong side of the fork. This can be done with the `whitelist` command line parameter. 
 ```

src/ethereum/crypto/finite_field.py

@@ -201,7 +201,7 @@ class GaloisField(tuple, Field):
     tuple of the non-leading coefficients of the defining polynomial. For
     example `x^3 + 2x^2 + 3x + 4` is `(2, 3, 4)`.
 
-    In practice the polynomial is likely to be be sparse and you should overload
+    In practice the polynomial is likely to be sparse and you should overload
     the `__mul__()` function to take advantage of this fact.
     """