vquic: drop msh3

It has never been properly functional in curl while there are several
alternatives that are.

Closes #17729

winbuild/Makefile.vc

@@ -164,23 +164,6 @@ NGHTTP2     = static
 USE_NGHTTP2 = false
 !ENDIF
 
-!IF "$(ENABLE_MSH3)"=="yes"
-# compatibility bit, WITH_MSH3 is the correct flag
-WITH_MSH3    = dll
-USE_MSH3     = true
-MSH3         = dll
-!ELSEIF "$(WITH_MSH3)"=="dll"
-USE_MSH3     = true
-MSH3         = dll
-!ELSEIF "$(WITH_MSH3)"=="static"
-USE_MSH3     = true
-MSH3         = static
-!ENDIF
-
-!IFNDEF USE_MSH3
-USE_MSH3 = false
-!ENDIF
-
 !IF "$(WITH_MBEDTLS)"=="dll" || "$(WITH_MBEDTLS)"=="static"
 USE_MBEDTLS = true
 MBEDTLS     = $(WITH_MBEDTLS)
@@ -281,10 +264,6 @@ CONFIG_NAME_LIB = $(CONFIG_NAME_LIB)-schannel
 CONFIG_NAME_LIB = $(CONFIG_NAME_LIB)-nghttp2-$(NGHTTP2)
 !ENDIF
 
-!IF "$(USE_MSH3)"=="true"
-CONFIG_NAME_LIB = $(CONFIG_NAME_LIB)-msh3
-!ENDIF
-
 !MESSAGE configuration name: $(CONFIG_NAME_LIB)
 
 # Note these directories are removed by this makefile's 'clean' so they should
@@ -308,7 +287,6 @@ $(MODE):
 	@SET CONFIG_NAME_LIB=$(CONFIG_NAME_LIB)
 	@SET MACHINE=$(MACHINE)
 	@SET USE_NGHTTP2=$(USE_NGHTTP2)
-	@SET USE_MSH3=$(USE_MSH3)
 	@SET USE_IDN=$(USE_IDN)
 	@SET USE_IPV6=$(USE_IPV6)
 	@SET USE_SSPI=$(USE_SSPI)

winbuild/MakefileBuild.vc

@@ -171,27 +171,6 @@ NGHTTP2_LIBS     = nghttp2.lib
 !ENDIF
 !ENDIF
 
-!IFDEF MSH3_PATH
-MSH3_INC_DIR     = $(MSH3_PATH)\include
-MSH3_LIB_DIR     = $(MSH3_PATH)\lib
-MSH3_LFLAGS      = $(MSH3_LFLAGS) "/LIBPATH:$(MSH3_LIB_DIR)"
-!ELSE
-MSH3_INC_DIR     = $(DEVEL_INCLUDE)
-MSH3_LIB_DIR     = $(DEVEL_LIB)
-!ENDIF
-
-!IF "$(WITH_MSH3)"=="dll"
-MSH3_CFLAGS      = /DUSE_MSH3 /I"$(MSH3_INC_DIR)"
-MSH3_LIBS        = msh3.lib
-!ELSEIF "$(WITH_MSH3)"=="static"
-MSH3_CFLAGS      = /DUSE_MSH3 /DMSH3_STATICLIB /I"$(MSH3_INC_DIR)"
-!IF EXISTS("$(NGHTTP2_LIB_DIR)\msh3_static.lib")
-MSH3_LIBS        = msh3_static.lib
-!ELSE
-MSH3_LIBS        = msh3.lib
-!ENDIF
-!ENDIF
-
 !IFDEF MBEDTLS_PATH
 MBEDTLS_INC_DIR  = $(MBEDTLS_PATH)\include
 MBEDTLS_LIB_DIR  = $(MBEDTLS_PATH)\lib
@@ -540,11 +519,6 @@ CFLAGS = $(CFLAGS) $(NGHTTP2_CFLAGS)
 LFLAGS = $(LFLAGS) $(NGHTTP2_LFLAGS) $(NGHTTP2_LIBS)
 !ENDIF
 
-!IF "$(USE_MSH3)"=="true"
-CFLAGS = $(CFLAGS) $(MSH3_CFLAGS)
-LFLAGS = $(LFLAGS) $(MSH3_LFLAGS) $(MSH3_LIBS)
-!ENDIF
-
 !IF "$(GEN_PDB)"=="true"
 CFLAGS = $(CFLAGS) $(CFLAGS_PDB) /Fd"$(LIB_DIROBJ)\$(PDB)"
 LFLAGS = $(LFLAGS) $(LFLAGS_PDB)
@@ -601,7 +575,6 @@ package: $(TARGET)
 $(TARGET): $(LIB_OBJS) $(LIB_DIROBJ) $(DIRDIST)
 	@echo Using SSL: $(USE_SSL)
 	@echo Using NGHTTP2: $(USE_NGHTTP2)
-	@echo Using MSH3: $(USE_MSH3)
 	@echo Using c-ares: $(USE_CARES)
 	@echo Using SSH2: $(USE_SSH2)
 	@echo Using SSH: $(USE_SSH)

winbuild/README.md

@@ -80,7 +80,6 @@ where `<options>` is one or many of:
                                    Defaults to sibling directory: `../deps`
  - `WITH_SSL=<dll/static>`       - Enable OpenSSL support, DLL or static
  - `WITH_NGHTTP2=<dll/static>`   - Enable HTTP/2 support, DLL or static
- - `WITH_MSH3=<dll/static>`      - Enable (experimental) HTTP/3 support, DLL or static
  - `WITH_MBEDTLS=<dll/static>`   - Enable mbedTLS support, DLL or static
  - `WITH_WOLFSSL=<dll/static>`   - Enable wolfSSL support, DLL or static
  - `WITH_CARES=<dll/static>`     - Enable c-ares support, DLL or static
@@ -106,7 +105,6 @@ where `<options>` is one or many of:
  - `MBEDTLS_PATH=<path>`         - Custom path for mbedTLS
  - `WOLFSSL_PATH=<path>`         - Custom path for wolfSSL
  - `NGHTTP2_PATH=<path>`         - Custom path for nghttp2
- - `MSH3_PATH=<path>`            - Custom path for msh3
  - `SSH_PATH=<path>`             - Custom path for libssh
  - `SSH2_PATH=<path>`            - Custom path for libssh2
  - `SSL_PATH=<path>`             - Custom path for OpenSSL