Python 3.12 and 3.13 emit "SyntaxWarning: invalid escape sequence"

[hacklschorsch]

Similar to https://tahoe-lafs.org/trac/tahoe-lafs/ticket/4158 and tahoe-lafs/tahoe-lafs#1427:

From https://stackoverflow.com/a/77531416/1181063:

Back in Python 3.6, using invalid escape sequences in string literals was deprecated (bpo-27364). Since then, attempting to use an invalid escape sequence has emitted a DeprecationWarning. This can often go unnoticed if you don't run Python with warnings enabled. DeprecationWarnings are silenced by default.

Python 3.12 upgraded the DeprecationWarning to a SyntaxWarning. SyntaxWarnings are emitted by the compiler when the code is parsed, not when it's being run, so they cannot be ignored using a runtime warning filter. Unlike DeprecationWarnings, SyntaxWarnings are displayed by default, which is why you're seeing it now. This increase in visibility was intentional. In a future version of Python, using invalid escape sequences in string literals is planned to eventually become a hard SyntaxError.

Setting up python3-txi2p-tahoe (0.3.7-3) ...
/usr/lib/python3/dist-packages/txi2p/test/test_plugins.py:69: SyntaxWarning: invalid escape sequence '\:'
  MemoryReactor(), "i2p:stats.i2p:apiEndpoint=tcp\:127.0.0.1\:2827")
/usr/lib/python3/dist-packages/txi2p/test/test_plugins.py:81: SyntaxWarning: invalid escape sequence '\:'
  MemoryReactor(), "i2p:stats.i2p:api=BOB:tunnelNick=spam:inport=12345:options=inbound.length\:5,outbound.length\:5")
/usr/lib/python3/dist-packages/txi2p/test/test_plugins.py:93: SyntaxWarning: invalid escape sequence '\:'
  MemoryReactor(), "i2p:stats.i2p:81:api=SAM:localPort=34444:options=inbound.length\:5,outbound.length\:5:sigType=foobar")
/usr/lib/python3/dist-packages/txi2p/test/test_plugins.py:125: SyntaxWarning: invalid escape sequence '\:'
  MemoryReactor(), "i2p:/tmp/testkeys.foo:apiEndpoint=tcp\:127.0.0.1\:2827")
/usr/lib/python3/dist-packages/txi2p/test/test_plugins.py:137: SyntaxWarning: invalid escape sequence '\:'
  MemoryReactor(), "i2p:/tmp/testkeys.foo:api=BOB:tunnelNick=spam:outport=23456:options=inbound.length\:5,outbound.length\:5")
/usr/lib/python3/dist-packages/txi2p/test/test_plugins.py:149: SyntaxWarning: invalid escape sequence '\:'
  MemoryReactor(), "i2p:/tmp/testkeys.foo:81:api=SAM:options=inbound.length\:5,outbound.length\:5:sigType=foobar")