Slow s3 exception raising due to usage pattern of jinja2

[jogo]

import time

from moto.s3.exceptions import MissingBucket

start = time.time()
for _ in range(1000):
    try:
        raise MissingBucket(bucket="foo")
    except MissingBucket:
        pass

print(round(time.time() - start, 2))

with moto 4.2.12: 1.58

cProfile data shows it's related to jinja2 usage. Some refactoring should be able to significantly speed this up.

Tue Dec 19 00:09:04 2023    pstats

         4532388 function calls (4276064 primitive calls) in 2.932 seconds

   Ordered by: cumulative time
   List reduced from 4319 to 30 due to restriction <30>

   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
   2658/1    0.010    0.000    2.975    2.975 {built-in method builtins.exec}
        1    0.003    0.003    2.975    2.975 foo.py:1(<module>)
     1000    0.002    0.000    2.501    0.003 /usr/local/lib/python3.8/dist-packages/moto/s3/exceptions.py:103(__init__)
     1000    0.002    0.000    2.499    0.002 /usr/local/lib/python3.8/dist-packages/moto/s3/exceptions.py:76(__init__)
     1000    0.002    0.000    2.496    0.002 /usr/local/lib/python3.8/dist-packages/moto/s3/exceptions.py:44(__init__)
     1000    0.009    0.000    2.494    0.002 /usr/local/lib/python3.8/dist-packages/moto/core/exceptions.py:58(__init__)
     2000    0.002    0.000    2.418    0.001 /usr/local/lib/python3.8/dist-packages/jinja2/environment.py:964(get_template)
     2000    0.007    0.000    2.415    0.001 /usr/local/lib/python3.8/dist-packages/jinja2/environment.py:939(_load_template)
     2000    0.007    0.000    2.393    0.001 /usr/local/lib/python3.8/dist-packages/jinja2/loaders.py:106(load)
     2000    0.008    0.000    2.359    0.001 /usr/local/lib/python3.8/dist-packages/jinja2/environment.py:717(compile)
     1000    0.003    0.000    1.433    0.001 /usr/local/lib/python3.8/dist-packages/jinja2/environment.py:1256(render)
26226/16158    0.014    0.000    1.411    0.000 {method 'join' of 'str' objects}

This means in code that has lots of calls to Moto for buckets that aren't set, there is a noticeable performance impact.