build/bake: enable fetch-by-commit for generated git contexts

Signed-off-by: CrazyMax <1951866+crazy-max@users.noreply.github.com>

Author: crazy-max

.github/workflows/bake.yml

@@ -414,7 +414,7 @@ jobs:
               return;
             }
 
-            const bakeSource = await new Build().gitContext({subdir: inpContext});
+            const bakeSource = await new Build().gitContext({subdir: inpContext, attrs: {'fetch-by-commit': 'true'}});
             await core.group(`Set bake source`, async () => {
               core.info(bakeSource);
             });
@@ -810,7 +810,7 @@ jobs:
             };
             const renderTemplate = value => Util.compileHandlebars(value, {noEscape: true}, {meta});
             
-            const bakeSource = await new Build().gitContext({subdir: inpContext});
+            const bakeSource = await new Build().gitContext({subdir: inpContext, attrs: {'fetch-by-commit': 'true'}});
             await core.group(`Set source output`, async () => {
               core.info(bakeSource);
               core.setOutput('source', bakeSource);

.github/workflows/build.yml

@@ -704,7 +704,7 @@ jobs:
             const renderTemplate = value => Util.compileHandlebars(value, {noEscape: true}, {meta});
             const toMultilineInput = value => value.split(/\r?\n/).map(line => line.trim()).filter(Boolean);
 
-            const buildContext = await new Build().gitContext({subdir: inpContext});
+            const buildContext = await new Build().gitContext({subdir: inpContext, attrs: {'fetch-by-commit': 'true'}});
             core.setOutput('context', buildContext);
             
             switch (inpOutput) {

test/go.Dockerfile

@@ -1,5 +1,3 @@
-# syntax=docker/dockerfile:1
-
 ARG GO_VERSION="1.25"
 ARG XX_VERSION="1.7.0"
 

test/hello.Dockerfile

@@ -1,5 +1,3 @@
-# syntax=docker/dockerfile:1
-
 FROM alpine AS base
 ARG TARGETPLATFORM
 ARG VERSION="unknown"