Fix issues with SSL certificates

Urllib's default handling of SSL certs is rather inconsistent: on linux/mac it
should use some system openssl path (which on mac may not be present), and on windows
it should use system certificate store.

Our old macOS workaround was apparently preventing usage of system certificate store
on windows as well, and using the old vendored cert.pem instead. The fix is to use SSL
certificates from OS certificate store, using truststore python module.

The truststore module requires python 3.10+ so we bump the minimum python dependency.

Author: wonder-sk

.github/workflows/autotests.yml

@@ -15,12 +15,12 @@ jobs:
 
       - uses: actions/setup-python@v2
         with:
-          python-version: "3.8"
+          python-version: "3.10"
 
       - name: Install python package dependencies
         run: |
           python -m pip install --upgrade pip
-          pip install python-dateutil pytz pytest pytest-cov pygeodiff coveralls
+          pip install python-dateutil pytz pytest pytest-cov pygeodiff truststore coveralls
 
       - name: Run tests
         run: |

.github/workflows/security_check.yml

@@ -13,7 +13,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v4
         with:
-          python-version: '3.9'
+          python-version: '3.10'
 
       - name: Install dependencies
         run: |

README.md

@@ -160,11 +160,11 @@ it is possible to run other commands without specifying username/password.
 
 ### Installing deps
 
-Python 3.7+ required. Create `mergin/deps` folder where [geodiff](https://github.com/MerginMaps/geodiff) lib is supposed to be and install dependencies:
+Python 3.10+ required. Create `mergin/deps` folder where [geodiff](https://github.com/MerginMaps/geodiff) lib is supposed to be and install dependencies:
 ```bash
     rm -r mergin/deps
     mkdir mergin/deps
-    pip install python-dateutil pytz
+    pip install python-dateutil pytz truststore
     pip install pygeodiff --target=mergin/deps
 ```