Remove use of deprecated `const` in WGSL

Bug: tint:699
Change-Id: Ic5ce39b5c144e25b3b40a991187566557e68754e
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/52240
Auto-Submit: James Price <jrprice@google.com>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>

src/dawn_native/CopyTextureForBrowserHelper.cpp

diff --git a/src/dawn_native/CopyTextureForBrowserHelper.cpp b/src/dawn_native/CopyTextureForBrowserHelper.cpp
index 4a0e829..5024846 100644
--- a/src/dawn_native/CopyTextureForBrowserHelper.cpp
+++ b/src/dawn_native/CopyTextureForBrowserHelper.cpp
@@ -40,7 +40,7 @@
             };
             [[binding(0), group(0)]] var<uniform> uniforms : Uniforms;
 
-            const texcoord : array<vec2<f32>, 3> = array<vec2<f32>, 3>(
+            let texcoord : array<vec2<f32>, 3> = array<vec2<f32>, 3>(
                 vec2<f32>(-0.5, 0.0),
                 vec2<f32>( 1.5, 0.0),
                 vec2<f32>( 0.5, 2.0));

src/dawn_native/QueryHelper.cpp

diff --git a/src/dawn_native/QueryHelper.cpp b/src/dawn_native/QueryHelper.cpp
index b9f58c5..70d9a9c 100644
--- a/src/dawn_native/QueryHelper.cpp
+++ b/src/dawn_native/QueryHelper.cpp
@@ -61,7 +61,7 @@
             [[group(0), binding(2)]] var<uniform> params : TimestampParams;
 
 
-            const sizeofTimestamp : u32 = 8u;
+            let sizeofTimestamp : u32 = 8u;
 
             [[stage(compute), workgroup_size(8, 1, 1)]]
             fn main([[builtin(global_invocation_id)]] GlobalInvocationID : vec3<u32>) {

src/tests/white_box/D3D12DescriptorHeapTests.cpp

diff --git a/src/tests/white_box/D3D12DescriptorHeapTests.cpp b/src/tests/white_box/D3D12DescriptorHeapTests.cpp
index 479e2b7..acda057 100644
--- a/src/tests/white_box/D3D12DescriptorHeapTests.cpp
+++ b/src/tests/white_box/D3D12DescriptorHeapTests.cpp
@@ -44,7 +44,7 @@
             [[stage(vertex)]] fn main(
                 [[builtin(vertex_index)]] VertexIndex : u32
             ) -> [[builtin(position)]] vec4<f32> {
-                const pos : array<vec2<f32>, 3> = array<vec2<f32>, 3>(
+                let pos : array<vec2<f32>, 3> = array<vec2<f32>, 3>(
                     vec2<f32>(-1.0,  1.0),
                     vec2<f32>( 1.0,  1.0),
                     vec2<f32>(-1.0, -1.0)
@@ -785,7 +785,7 @@
             [[stage(vertex)]] fn main(
                 [[builtin(vertex_index)]] VertexIndex : u32
             ) -> [[builtin(position)]] vec4<f32> {
-                const pos : array<vec2<f32>, 3> = array<vec2<f32>, 3>(
+                let pos : array<vec2<f32>, 3> = array<vec2<f32>, 3>(
                     vec2<f32>(-1.0,  1.0),
                     vec2<f32>( 1.0,  1.0),
                     vec2<f32>(-1.0, -1.0)

src/tests/white_box/D3D12ResidencyTests.cpp

diff --git a/src/tests/white_box/D3D12ResidencyTests.cpp b/src/tests/white_box/D3D12ResidencyTests.cpp
index e22dc73..ea44164 100644
--- a/src/tests/white_box/D3D12ResidencyTests.cpp
+++ b/src/tests/white_box/D3D12ResidencyTests.cpp
@@ -342,7 +342,7 @@
             [[stage(vertex)]] fn main(
                 [[builtin(vertex_index)]] VertexIndex : u32
             ) -> [[builtin(position)]] vec4<f32> {
-                const pos : array<vec2<f32>, 3> = array<vec2<f32>, 3>(
+                let pos : array<vec2<f32>, 3> = array<vec2<f32>, 3>(
                     vec2<f32>(-1.0,  1.0),
                     vec2<f32>( 1.0,  1.0),
                     vec2<f32>(-1.0, -1.0)