Use windows-2019 image in CI

This commit squashes some existing commits, all related to
the Azure Pipeline CI builds.

WHAT:
1. Use `windows-2019` image in CI
2. Switch Qt download mirror to `https`
3. Replace MSVC-2017 builds: MSVC-2017 is not present in `windows-2019`
4. Fix broken mingw builds

WHY:
As you can see in a recent Azure Pipelines build, the Windows Server
2016 image is now deprecated:
https://dev.azure.com/miurahr/github/_build/results?buildId=4687&view=logs&j=c4497b2b-649a-591e-539b-0d716883e33e

The newer `vmImage: 'windows-2022'` would work too, see
https://docs.microsoft.com/en-us/azure/devops/pipelines/agents/hosted?view=azure-devops&tabs=yaml

MINGW:
The existing mingw builds were a little bit broken because the `Path`
environment variable did not include the mingw toolchain installed with
`aqt install-tool`, so the Chocolatey mingw was being used.
This change fixes that by adding parameters to BuildJob that are
specific to each mingw toolchain and fixing the code that sets the Path
environment variable in Powershell.

ci/generate_azure_pipelines_matrices.py

@@ -4,12 +4,13 @@ This sets variables for a matrix of QT versions to test downloading against with
 import collections
 import json
 import random
+import re
 from itertools import product
 from typing import Dict, Optional
 
 MIRRORS = [
     "https://ftp.jaist.ac.jp/pub/qtproject",
-    "http://ftp1.nluug.nl/languages/qt",
+    "https://ftp1.nluug.nl/languages/qt",
     "https://mirrors.dotsrc.org/qtproject",
 ]
 
@@ -30,6 +31,7 @@ class BuildJob:
         output_dir=None,
         list_options=None,
         spec=None,
+        mingw_variant: str = "",
         tool_options: Optional[Dict[str, str]] = None,
     ):
         self.command = command
@@ -41,6 +43,7 @@ class BuildJob:
         self.module = module
         self.mirror = mirror
         self.subarchives = subarchives
+        self.mingw_variant: str = mingw_variant
         self.list_options = list_options if list_options else {}
         self.tool_options: Dict[str, str] = tool_options if tool_options else {}
         # `steps.yml` assumes that qt_version is the highest version that satisfies spec
@@ -55,6 +58,12 @@ class BuildJob:
     def win_qt_bindir(self) -> str:
         return self.qt_bindir(sep='\\')
 
+    def mingw_folder(self) -> str:
+        if not self.mingw_variant:
+            return ""
+        match = re.match(r"^win(\d+)_(mingw\d+)$", self.mingw_variant)
+        return f"{match[2]}_{match[1]}"
+
 
 class PlatformBuildJobs:
     def __init__(self, platform, build_jobs):
@@ -95,11 +104,11 @@ windows_build_jobs.extend(
     [
         BuildJob(
             "install-qt",
-            "5.14.2",
+            "5.15.2",
             "windows",
             "desktop",
-            "win64_msvc2017_64",
-            "msvc2017_64",
+            "win32_msvc2019",
+            "msvc2019",
             mirror=random.choice(MIRRORS),
         ),
         BuildJob(
@@ -107,8 +116,9 @@ windows_build_jobs.extend(
             "5.14.2",
             "windows",
             "desktop",
-            "win32_msvc2017",
-            "msvc2017",
+            "win32_mingw73",
+            "mingw73_32",
+            mingw_variant="win32_mingw730",
             mirror=random.choice(MIRRORS),
         ),
         BuildJob(
@@ -127,6 +137,7 @@ windows_build_jobs.extend(
             "desktop",
             "win64_mingw81",
             "mingw81_64",
+            mingw_variant="win64_mingw810",
             mirror=random.choice(MIRRORS),
         ),
         # Known issue with Azure-Pipelines environment: it has a pre-installed mingw81 which cause link error.
@@ -146,8 +157,8 @@ windows_build_jobs.extend(
             "5.9.0",
             "windows",
             "desktop",
-            "win64_msvc2017_64",
-            "msvc2017_64",
+            "win64_msvc2015_64",
+            "msvc2015_64",
             module="qtcharts qtnetworkauth",
             mirror=random.choice(MIRRORS),
         ),
@@ -156,8 +167,9 @@ windows_build_jobs.extend(
             "5.14.2",
             "windows",
             "desktop",
-            "win64_msvc2017_64",
-            "msvc2017_64",
+            "win64_mingw73",
+            "mingw73_64",
+            mingw_variant="win64_mingw730",
             spec=">1,<5.15",  # Don't redirect output! Must be wrapped in quotes!
             mirror=random.choice(MIRRORS),
         ),
@@ -338,6 +350,8 @@ for platform_build_job in all_platform_build_jobs:
                 ("QT_BASE_MIRROR", build_job.mirror if build_job.mirror else ""),
                 ("SUBARCHIVES", build_job.subarchives if build_job.subarchives else ""),
                 ("SPEC", build_job.spec if build_job.spec else ""),
+                ("MINGW_VARIANT", build_job.mingw_variant),
+                ("MINGW_FOLDER", build_job.mingw_folder()),
                 ("HAS_EXTENSIONS", build_job.list_options.get("HAS_EXTENSIONS", "False")),
                 ("USE_EXTENSION", build_job.list_options.get("USE_EXTENSION", "None")),
                 ("OUTPUT_DIR", build_job.output_dir if build_job.output_dir else ""),