ci: fix Windows curl llvm download failure (#2089)

For a few days now, the Windows CI variants have been almost always
failing due to unexplained inability to curl download the pre-built
LLVM that we stashed on a Google drive, which has worked flawlessly
for over a year.

J.F. Panisset suggested:

> Could be a wild goose chase, but a direction to look in with your
> Windows / curl issue would be SSL certificate verification. Windows
> uses some kind of magic process to update its store of recognized CA
> root certs, but since a Windows runner is a "fresh" Windows VM every
> time, it could be that it is missing an updated cert required to
> verify the https URL you are downloading from (assuming that's using
> a cert anchored to a root CA not in that base WIndows image). I've
> seen issues like that on Windows systems with limited Internet
> access. If you try curl --insecure to (temporarily) bypass
> certificate verification, are you able to download what you need?

And sure enough, adding --insecure clears it right up.

Signed-off-by: Larry Gritz <lg@larrygritz.com>

Author: lgritz

src/build-scripts/gh-win-installdeps.bash

@@ -127,7 +127,7 @@ elif [[ "$LLVM_GOOGLE_DRIVE_ID" != "" ]] then
     pushd $HOME/llvm
     #LLVM_GOOGLE_DRIVE_ID="1uy7PNVlTQ-H56unXGOS6siRWtNcdS1J7"
     LLVM_ZIP_FILENAME=llvm-build.zip
-    time curl -L "https://drive.usercontent.google.com/download?id=${LLVM_GOOGLE_DRIVE_ID}&confirm=xxx" -o $LLVM_ZIP_FILENAME
+    time curl --insecure -L "https://drive.usercontent.google.com/download?id=${LLVM_GOOGLE_DRIVE_ID}&confirm=xxx" -o $LLVM_ZIP_FILENAME
     unzip $LLVM_ZIP_FILENAME > /dev/null
     export LLVM_ROOT=$PWD/llvm-build
     popd