[MRG] bump BIDS_VERSION to 1.7.0

[sappelhoff]

PR Description

To my knowledge, we are fully compliant with 1.7.0

Merge checklist

Maintainer, please confirm the following before merging:

• All comments resolved
• This is not your own PR
• All CIs are happy
• PR title starts with [MRG]
• whats_new.rst is updated
• PR description includes phrase "closes <#issue-number>"

[codecov]

Codecov Report

Merging #997 (74c8fbe) into main (5e65124) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main     #997   +/-   ##
=======================================
  Coverage   95.11%   95.11%           
=======================================
  Files          25       25           
  Lines        3744     3744           
=======================================
  Hits         3561     3561           
  Misses        183      183           

Impacted Files	Coverage Δ
mne_bids/config.py	97.59% <100.00%> (ø)

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[hoechenberger]

Thanks @sappelhoff