Update cryptography requirement from >=2.6,<37.0 to >=2.6,<38.0

Updates the requirements on [cryptography](https://github.com/pyca/cryptography) to permit the latest version.
- [Release notes](https://github.com/pyca/cryptography/releases)
- [Changelog](https://github.com/pyca/cryptography/blob/main/CHANGELOG.rst)
- [Commits](https://github.com/pyca/cryptography/compare/2.6...37.0.0)

---
updated-dependencies:
- dependency-name: cryptography
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/pyproject.toml b/pyproject.toml
index 9ab0385..e287d3a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -42,7 +42,7 @@ h2 = {version=">=4.1.0", optional=true, python=">=3.6.2"}
 requests-toolbelt = {version="^0.9.1", optional=true}
 requests = {version="^2.23.0", optional=true}
 idna = {version=">=2.1,<4.0", optional=true}
-cryptography = {version=">=2.6,<37.0", optional=true}
+cryptography = {version=">=2.6,<38.0", optional=true}
 trio = {version=">=0.14,<0.21", optional=true}
 curio = {version="^1.2", optional=true}
 sniffio = {version="^1.1", optional=true}