requirements: Refresh the static required versions used in tox environments.
diff --git a/requirements/cov-requirements.txt b/requirements/cov-requirements.txt
index 24a5cb9..4bb1048 100644
--- a/requirements/cov-requirements.txt
+++ b/requirements/cov-requirements.txt
@@ -1,12 +1,12 @@
 coverage==4.4
 pytest-cov==2.10.1
-pytest==6.1.2
-Cython==0.29.21
+pytest==6.2.4
+Cython==0.29.24
 ## The following requirements were added by pip freeze:
-attrs==20.3.0
+attrs==21.2.0
 iniconfig==1.1.1
-packaging==20.7
+packaging==21.0
 pluggy==0.13.1
-py==1.9.0
+py==1.10.0
 pyparsing==2.4.7
 toml==0.10.2
diff --git a/requirements/dev-requirements.txt b/requirements/dev-requirements.txt
index 5ad8be9..cef33fd 100644
--- a/requirements/dev-requirements.txt
+++ b/requirements/dev-requirements.txt
@@ -1,27 +1,26 @@
 pexpect==4.8.0
-pylint==2.6.0
+pylint==2.10.2
 # Pytest 6.0.0 doesn't play well with pylint
-pytest==6.1.2
+pytest==6.2.4
 pytest-datafiles==2.0
 pytest-env==0.6.2
-pytest-xdist==2.1.0
+pytest-xdist==2.3.0
 pytest-timeout==1.4.2
 pyftpdlib==1.5.6
 ## The following requirements were added by pip freeze:
-apipkg==1.5
-astroid==2.4.2
-attrs==20.3.0
-execnet==1.7.1
+astroid==2.7.2
+attrs==21.2.0
+execnet==1.9.0
 iniconfig==1.1.1
-isort==5.6.4
-lazy-object-proxy==1.4.3
+isort==5.9.3
+lazy-object-proxy==1.6.0
 mccabe==0.6.1
-packaging==20.7
+packaging==21.0
+platformdirs==2.2.0
 pluggy==0.13.1
-ptyprocess==0.6.0
-py==1.9.0
+ptyprocess==0.7.0
+py==1.10.0
 pyparsing==2.4.7
 pytest-forked==1.3.0
-six==1.15.0
 toml==0.10.2
 wrapt==1.12.1
diff --git a/requirements/requirements.txt b/requirements/requirements.txt
index 0d4f7d7..77eebc2 100644
--- a/requirements/requirements.txt
+++ b/requirements/requirements.txt
@@ -1,15 +1,15 @@
-click==7.1.2
-grpcio==1.34.0
-Jinja2==2.11.2
-pluginbase==1.0.0
-protobuf==3.14.0
-psutil==5.7.3
-ruamel.yaml==0.16.12
-ruamel.yaml.clib==0.2.2
-setuptools==49.1.3
-pyroaring==0.2.9
-ujson==4.0.1
-python-dateutil==2.8.1
+click==8.0.1
+grpcio==1.39.0
+Jinja2==3.0.1
+pluginbase==1.0.1
+protobuf==3.17.3
+psutil==5.8.0
+ruamel.yaml==0.17.13
+ruamel.yaml.clib==0.2.6
+setuptools==44.1.1
+pyroaring==0.3.3
+ujson==4.1.0
+python-dateutil==2.8.2
 ## The following requirements were added by pip freeze:
-MarkupSafe==1.1.1
-six==1.15.0
+MarkupSafe==2.0.1
+six==1.16.0