Disable appveyor cache

[aidanhs]

Reverts just appveyor part of #40780. r? @aturon

[aturon]

Thanks!

@bors: r+ p=100 (unblock the queue)

[bors]

📌 Commit fe0fbbf has been approved by aturon

[bors]

⌛ Testing commit fe0fbbf with merge ee9dd1a...

[bors]

💔 Test failed - status-appveyor

[aidanhs]

FAILED: lib/libLLVMAArch64Info.a 
cmd.exe /C "cd . && "C:\Program Files (x86)\CMake\bin\cmake.exe" -E remove lib\libLLVMAArch64Info.a && C:\projects\rust\mingw64\bin\ar.exe qc lib\libLLVMAArch64Info.a  lib/Target/AArch64/TargetInfo/CMakeFiles/LLVMAArch64Info.dir/AArch64TargetInfo.cpp.obj && C:\projects\rust\mingw64\bin\ranlib.exe lib\libLLVMAArch64Info.a && cd ."
C:\projects\rust\mingw64\bin\ranlib.exe: unable to rename 'lib\libLLVMAArch64Info.a'; reason: Permission denied
[1140/1629] Linking CXX static library lib\libLLVMAArch64CodeGen.a
ninja: build stopped: subcommand failed.
thread 'main' panicked at '
command did not execute successfully, got: exit code: 1
build script failed, must exit now', C:\Users\appveyor\.cargo\registry\src\github.com-1ecc6299db9ec823\cmake-0.1.22\src\lib.rs:617
note: Run with `RUST_BACKTRACE=1` for a backtrace.
	finished in 271.254
Build completed unsuccessfully in 0:06:40
Command exited with code 101
cat %CD%/sccache.log
DEBUG:sccache::cache::cache: Trying S3Cache(rust-lang-ci-sccache.s3.amazonaws.com)
DEBUG:sccache::server: handle_client: compile

#40546

[frewsxcv]

@bors retry

That's an intermittent error I think

[bors]

⌛ Testing commit fe0fbbf with merge 47325da...

[bors]

💔 Test failed - status-travis

[frewsxcv]

@bors retry

[bors]

⌛ Testing commit fe0fbbf with merge 6afa0d4...

[bors]

☀️ Test successful - status-appveyor, status-travis
Approved by: aturon
Pushing 6afa0d4 to master...