tests: vyper: fix compilation failure

0.4 is now used in newer Python versions, which we don't yet support fully

  Testing vyper integration of /opt/hostedtoolcache/Python/3.12.7/x64/bin/crytic-compile
  ERROR:CryticCompile:missing type annotation

    (hint: did you mean something like `for i: uint256 in ...`?)

    line 111:4
         110     refund: uint256 = 0
    ---> 111     for i in range(MAX_BIDS):
    -------------^
         112         # Note that loop may break sooner than 128 iterations if i >= _numBids

  ERROR:CryticCompile:Vyper compilation errored
  vyper test failed

scripts/ci_test_vyper.sh

@@ -2,7 +2,7 @@
 
 ### Test vyper integration
 
-pip install vyper
+pip install 'vyper>=0.3.7,<0.4'
 
 echo "Testing vyper integration of $(realpath "$(which crytic-compile)")"