Allow tuples in checksums dictionary values

[jngrad]

With EasyBuild 4.9.4, the following syntax doesn't pass verify_checksum():

checksums = [{
  'espresso-237c376.tar.gz': ('sha256', '67cb83e0327fdb03e02631bfd225d11e6b5465b8c3d4ee0d7b6c0dc504f9365a'),
}]

== 2025-01-17 16:39:34,229 easyblock.py:4297 WARNING build failed (first 300 chars):
  Invalid checksum spec '['sha256', 'e08df57f132cf59dee1af91a93547e407bb442d4caa0946a136699a43d54ae36']':
  should be a string (MD5 or SHA256), 2-tuple (type, value), or tuple of alternative checksum specs.

Yet, the documentation mentions this syntax is allowed. Looking into the method code reveals the following branch is not taken:

easybuild-framework/easybuild/tools/filetools.py

Lines 1290 to 1295 in 71cbb00

	elif isinstance(checksum, tuple):
	# if checksum is specified as a tuple, it could either be specifying:
	# * the type of checksum + the checksum value
	# * a set of alternative valid checksums to consider => recursive call
	if len(checksum) == 2 and checksum[0] in CHECKSUM_FUNCTIONS:
	typ, checksum = checksum

The error message suggests to me that a parser is converting the Python syntax to a JSON-like syntax, i.e. tuples become lists.

When rewriting the condition as isinstance(checksum, (list, tuple)), the program runs as expected.