[new release] dune (1.7.2)

[rgrinberg]

CHANGES:

• Add ${corrected-suffix}, ${library-name} and a few other
  variables to the list of variables to upgrade. This fixes the
  support for various framework producing corrections (Add corrected-suffix to the list of known variables when upgrading dune#1840, Upgrade the library-name, impl-files and intf-files variables dune#1853,
  @diml)

• Fix $ dune subst failing because the build directory wasn't set. (Fix dune subst not setting build root dune#1854, fix
  internal error: cannot use build dir before its set dune#1846, @rgrinberg)

• Configurator: Add warning to Pkg_config.query when a full package expression
  is used. Add Pkg_config.query_expr for cases when the full power of
  pkg-config's querying is needed (Fix pkg-config quoting behavior dune#1842, fix [configurator] New quoting rules may create problems. dune#1833, @rgrinberg)

• Fix unavailable, optional implementations eagerly breaking the build (Fix #1856 dune#1857,
  fix Error if dependencies are unavailable for an optional implementation dune#1856, @rgrinberg)

[camelus]

☀️ All lint checks passed a65d41c

• These packages passed lint tests: dune.1.7.2

---

☀️ Installability check (10505 → 10506)

• new installable packages (1): dune.1.7.2

[rgrinberg]

All the failures are the usual offenders. I think this is good to go.

[kit-ty-kate]

Thanks!